/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <drm/drm_atomic_helper.h>

#include "display/intel_dp.h"

#include "i915_drv.h"
#include "intel_drv.h"
#include "intel_psr.h"
#include "intel_sprite.h"

/**
 * DOC: Panel Self Refresh (PSR/SRD)
 *
 * Since Haswell Display controller supports Panel Self-Refresh on display
 * panels witch have a remote frame buffer (RFB) implemented according to PSR
 * spec in eDP1.3. PSR feature allows the display to go to lower standby states
 * when system is idle but display is on as it eliminates display refresh
 * request to DDR memory completely as long as the frame buffer for that
 * display is unchanged.
 *
 * Panel Self Refresh must be supported by both Hardware (source) and
 * Panel (sink).
 *
 * PSR saves power by caching the framebuffer in the panel RFB, which allows us
 * to power down the link and memory controller. For DSI panels the same idea
 * is called "manual mode".
 *
 * The implementation uses the hardware-based PSR support which automatically
 * enters/exits self-refresh mode. The hardware takes care of sending the
 * required DP aux message and could even retrain the link (that part isn't
 * enabled yet though). The hardware also keeps track of any frontbuffer
 * changes to know when to exit self-refresh mode again. Unfortunately that
 * part doesn't work too well, hence why the i915 PSR support uses the
 * software frontbuffer tracking to make sure it doesn't miss a screen
 * update. For this integration intel_psr_invalidate() and intel_psr_flush()
 * get called by the frontbuffer tracking code. Note that because of locking
 * issues the self-refresh re-enable code is done from a work queue, which
 * must be correctly synchronized/cancelled when shutting down the pipe."
 */

static bool psr_global_enabled(u32 debug)
{
        switch (debug & I915_PSR_DEBUG_MODE_MASK) {
        case I915_PSR_DEBUG_DEFAULT:
                return i915_modparams.enable_psr;
        case I915_PSR_DEBUG_DISABLE:
                return false;
        default:
                return true;
        }
}

static bool intel_psr2_enabled(struct drm_i915_private *dev_priv,
                               const struct intel_crtc_state *crtc_state)
{
        /* Cannot enable DSC and PSR2 simultaneously */
        WARN_ON(crtc_state->dsc_params.compression_enable &&
                crtc_state->has_psr2);

        switch (dev_priv->psr.debug & I915_PSR_DEBUG_MODE_MASK) {
        case I915_PSR_DEBUG_DISABLE:
        case I915_PSR_DEBUG_FORCE_PSR1:
                return false;
        default:
                return crtc_state->has_psr2;
        }
}

static int edp_psr_shift(enum transcoder cpu_transcoder)
{
        switch (cpu_transcoder) {
        case TRANSCODER_A:
                return EDP_PSR_TRANSCODER_A_SHIFT;
        case TRANSCODER_B:
                return EDP_PSR_TRANSCODER_B_SHIFT;
        case TRANSCODER_C:
                return EDP_PSR_TRANSCODER_C_SHIFT;
        default:
                MISSING_CASE(cpu_transcoder);
                /* fallthrough */
        case TRANSCODER_EDP:
                return EDP_PSR_TRANSCODER_EDP_SHIFT;
        }
}

void intel_psr_irq_control(struct drm_i915_private *dev_priv, u32 debug)
{
        u32 debug_mask, mask;
        enum transcoder cpu_transcoder;
        u32 transcoders = BIT(TRANSCODER_EDP);

        if (INTEL_GEN(dev_priv) >= 8)
                transcoders |= BIT(TRANSCODER_A) |
                               BIT(TRANSCODER_B) |
                               BIT(TRANSCODER_C);

        debug_mask = 0;
        mask = 0;
        for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders) {
                int shift = edp_psr_shift(cpu_transcoder);

                mask |= EDP_PSR_ERROR(shift);
                debug_mask |= EDP_PSR_POST_EXIT(shift) |
                              EDP_PSR_PRE_ENTRY(shift);
        }

        if (debug & I915_PSR_DEBUG_IRQ)
                mask |= debug_mask;

        I915_WRITE(EDP_PSR_IMR, ~mask);
}

static void psr_event_print(u32 val, bool psr2_enabled)
{
        DRM_DEBUG_KMS("PSR exit events: 0x%x\n", val);
        if (val & PSR_EVENT_PSR2_WD_TIMER_EXPIRE)
                DRM_DEBUG_KMS("\tPSR2 watchdog timer expired\n");
        if ((val & PSR_EVENT_PSR2_DISABLED) && psr2_enabled)
                DRM_DEBUG_KMS("\tPSR2 disabled\n");
        if (val & PSR_EVENT_SU_DIRTY_FIFO_UNDERRUN)
                DRM_DEBUG_KMS("\tSU dirty FIFO underrun\n");
        if (val & PSR_EVENT_SU_CRC_FIFO_UNDERRUN)
                DRM_DEBUG_KMS("\tSU CRC FIFO underrun\n");
        if (val & PSR_EVENT_GRAPHICS_RESET)
                DRM_DEBUG_KMS("\tGraphics reset\n");
        if (val & PSR_EVENT_PCH_INTERRUPT)
                DRM_DEBUG_KMS("\tPCH interrupt\n");
        if (val & PSR_EVENT_MEMORY_UP)
                DRM_DEBUG_KMS("\tMemory up\n");
        if (val & PSR_EVENT_FRONT_BUFFER_MODIFY)
                DRM_DEBUG_KMS("\tFront buffer modification\n");
        if (val & PSR_EVENT_WD_TIMER_EXPIRE)
                DRM_DEBUG_KMS("\tPSR watchdog timer expired\n");
        if (val & PSR_EVENT_PIPE_REGISTERS_UPDATE)
                DRM_DEBUG_KMS("\tPIPE registers updated\n");
        if (val & PSR_EVENT_REGISTER_UPDATE)
                DRM_DEBUG_KMS("\tRegister updated\n");
        if (val & PSR_EVENT_HDCP_ENABLE)
                DRM_DEBUG_KMS("\tHDCP enabled\n");
        if (val & PSR_EVENT_KVMR_SESSION_ENABLE)
                DRM_DEBUG_KMS("\tKVMR session enabled\n");
        if (val & PSR_EVENT_VBI_ENABLE)
                DRM_DEBUG_KMS("\tVBI enabled\n");
        if (val & PSR_EVENT_LPSP_MODE_EXIT)
                DRM_DEBUG_KMS("\tLPSP mode exited\n");
        if ((val & PSR_EVENT_PSR_DISABLE) && !psr2_enabled)
                DRM_DEBUG_KMS("\tPSR disabled\n");
}

void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
{
        u32 transcoders = BIT(TRANSCODER_EDP);
        enum transcoder cpu_transcoder;
        ktime_t time_ns =  ktime_get();
        u32 mask = 0;

        if (INTEL_GEN(dev_priv) >= 8)
                transcoders |= BIT(TRANSCODER_A) |
                               BIT(TRANSCODER_B) |
                               BIT(TRANSCODER_C);

        for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders) {
                int shift = edp_psr_shift(cpu_transcoder);

                if (psr_iir & EDP_PSR_ERROR(shift)) {
                        DRM_WARN("[transcoder %s] PSR aux error\n",
                                 transcoder_name(cpu_transcoder));

                        dev_priv->psr.irq_aux_error = true;

                        /*
                         * If this interruption is not masked it will keep
                         * interrupting so fast that it prevents the scheduled
                         * work to run.
                         * Also after a PSR error, we don't want to arm PSR
                         * again so we don't care about unmask the interruption
                         * or unset irq_aux_error.
                         */
                        mask |= EDP_PSR_ERROR(shift);
                }

                if (psr_iir & EDP_PSR_PRE_ENTRY(shift)) {
                        dev_priv->psr.last_entry_attempt = time_ns;
                        DRM_DEBUG_KMS("[transcoder %s] PSR entry attempt in 2 vblanks\n",
                                      transcoder_name(cpu_transcoder));
                }

                if (psr_iir & EDP_PSR_POST_EXIT(shift)) {
                        dev_priv->psr.last_exit = time_ns;
                        DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
                                      transcoder_name(cpu_transcoder));

                        if (INTEL_GEN(dev_priv) >= 9) {
                                u32 val = I915_READ(PSR_EVENT(cpu_transcoder));
                                bool psr2_enabled = dev_priv->psr.psr2_enabled;

                                I915_WRITE(PSR_EVENT(cpu_transcoder), val);
                                psr_event_print(val, psr2_enabled);
                        }
                }
        }

        if (mask) {
                mask |= I915_READ(EDP_PSR_IMR);
                I915_WRITE(EDP_PSR_IMR, mask);

                schedule_work(&dev_priv->psr.work);
        }
}

static bool intel_dp_get_alpm_status(struct intel_dp *intel_dp)
{
        u8 alpm_caps = 0;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
                              &alpm_caps) != 1)
                return false;
        return alpm_caps & DP_ALPM_CAP;
}

static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
{
        u8 val = 8; /* assume the worst if we can't read the value */

        if (drm_dp_dpcd_readb(&intel_dp->aux,
                              DP_SYNCHRONIZATION_LATENCY_IN_SINK, &val) == 1)
                val &= DP_MAX_RESYNC_FRAME_COUNT_MASK;
        else
                DRM_DEBUG_KMS("Unable to get sink synchronization latency, assuming 8 frames\n");
        return val;
}

static u16 intel_dp_get_su_x_granulartiy(struct intel_dp *intel_dp)
{
        u16 val;
        ssize_t r;

        /*
         * Returning the default X granularity if granularity not required or
         * if DPCD read fails
         */
        if (!(intel_dp->psr_dpcd[1] & DP_PSR2_SU_GRANULARITY_REQUIRED))
                return 4;

        r = drm_dp_dpcd_read(&intel_dp->aux, DP_PSR2_SU_X_GRANULARITY, &val, 2);
        if (r != 2)
                DRM_DEBUG_KMS("Unable to read DP_PSR2_SU_X_GRANULARITY\n");

        /*
         * Spec says that if the value read is 0 the default granularity should
         * be used instead.
         */
        if (r != 2 || val == 0)
                val = 4;

        return val;
}

void intel_psr_init_dpcd(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv =
                to_i915(dp_to_dig_port(intel_dp)->base.base.dev);

        drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT, intel_dp->psr_dpcd,
                         sizeof(intel_dp->psr_dpcd));

        if (!intel_dp->psr_dpcd[0])
                return;
        DRM_DEBUG_KMS("eDP panel supports PSR version %x\n",
                      intel_dp->psr_dpcd[0]);

        if (drm_dp_has_quirk(&intel_dp->desc, DP_DPCD_QUIRK_NO_PSR)) {
                DRM_DEBUG_KMS("PSR support not currently available for this panel\n");
                return;
        }

        if (!(intel_dp->edp_dpcd[1] & DP_EDP_SET_POWER_CAP)) {
                DRM_DEBUG_KMS("Panel lacks power state control, PSR cannot be enabled\n");
                return;
        }

        dev_priv->psr.sink_support = true;
        dev_priv->psr.sink_sync_latency =
                intel_dp_get_sink_sync_latency(intel_dp);

        WARN_ON(dev_priv->psr.dp);
        dev_priv->psr.dp = intel_dp;

        if (INTEL_GEN(dev_priv) >= 9 &&
            (intel_dp->psr_dpcd[0] == DP_PSR2_WITH_Y_COORD_IS_SUPPORTED)) {
                bool y_req = intel_dp->psr_dpcd[1] &
                             DP_PSR2_SU_Y_COORDINATE_REQUIRED;
                bool alpm = intel_dp_get_alpm_status(intel_dp);

                /*
                 * All panels that supports PSR version 03h (PSR2 +
                 * Y-coordinate) can handle Y-coordinates in VSC but we are
                 * only sure that it is going to be used when required by the
                 * panel. This way panel is capable to do selective update
                 * without a aux frame sync.
                 *
                 * To support PSR version 02h and PSR version 03h without
                 * Y-coordinate requirement panels we would need to enable
                 * GTC first.
                 */
                dev_priv->psr.sink_psr2_support = y_req && alpm;
                DRM_DEBUG_KMS("PSR2 %ssupported\n",
                              dev_priv->psr.sink_psr2_support ? "" : "not ");

                if (dev_priv->psr.sink_psr2_support) {
                        dev_priv->psr.colorimetry_support =
                                intel_dp_get_colorimetry_status(intel_dp);
                        dev_priv->psr.su_x_granularity =
                                intel_dp_get_su_x_granulartiy(intel_dp);
                }
        }
}

static void intel_psr_setup_vsc(struct intel_dp *intel_dp,
                                const struct intel_crtc_state *crtc_state)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct dp_sdp psr_vsc;

        if (dev_priv->psr.psr2_enabled) {
                /* Prepare VSC Header for SU as per EDP 1.4 spec, Table 6.11 */
                memset(&psr_vsc, 0, sizeof(psr_vsc));
                psr_vsc.sdp_header.HB0 = 0;
                psr_vsc.sdp_header.HB1 = 0x7;
                if (dev_priv->psr.colorimetry_support) {
                        psr_vsc.sdp_header.HB2 = 0x5;
                        psr_vsc.sdp_header.HB3 = 0x13;
                } else {
                        psr_vsc.sdp_header.HB2 = 0x4;
                        psr_vsc.sdp_header.HB3 = 0xe;
                }
        } else {
                /* Prepare VSC packet as per EDP 1.3 spec, Table 3.10 */
                memset(&psr_vsc, 0, sizeof(psr_vsc));
                psr_vsc.sdp_header.HB0 = 0;
                psr_vsc.sdp_header.HB1 = 0x7;
                psr_vsc.sdp_header.HB2 = 0x2;
                psr_vsc.sdp_header.HB3 = 0x8;
        }

        intel_dig_port->write_infoframe(&intel_dig_port->base,
                                        crtc_state,
                                        DP_SDP_VSC, &psr_vsc, sizeof(psr_vsc));
}

static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 aux_clock_divider, aux_ctl;
        int i;
        static const u8 aux_msg[] = {
                [0] = DP_AUX_NATIVE_WRITE << 4,
                [1] = DP_SET_POWER >> 8,
                [2] = DP_SET_POWER & 0xff,
                [3] = 1 - 1,
                [4] = DP_SET_POWER_D0,
        };
        u32 psr_aux_mask = EDP_PSR_AUX_CTL_TIME_OUT_MASK |
                           EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK |
                           EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK |
                           EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK;

        BUILD_BUG_ON(sizeof(aux_msg) > 20);
        for (i = 0; i < sizeof(aux_msg); i += 4)
                I915_WRITE(EDP_PSR_AUX_DATA(i >> 2),
                           intel_dp_pack_aux(&aux_msg[i], sizeof(aux_msg) - i));

        aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);

        /* Start with bits set for DDI_AUX_CTL register */
        aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, sizeof(aux_msg),
                                             aux_clock_divider);

        /* Select only valid bits for SRD_AUX_CTL */
        aux_ctl &= psr_aux_mask;
        I915_WRITE(EDP_PSR_AUX_CTL, aux_ctl);
}

static void intel_psr_enable_sink(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u8 dpcd_val = DP_PSR_ENABLE;

        /* Enable ALPM at sink for psr2 */
        if (dev_priv->psr.psr2_enabled) {
                drm_dp_dpcd_writeb(&intel_dp->aux, DP_RECEIVER_ALPM_CONFIG,
                                   DP_ALPM_ENABLE);
                dpcd_val |= DP_PSR_ENABLE_PSR2 | DP_PSR_IRQ_HPD_WITH_CRC_ERRORS;
        } else {
                if (dev_priv->psr.link_standby)
                        dpcd_val |= DP_PSR_MAIN_LINK_ACTIVE;

                if (INTEL_GEN(dev_priv) >= 8)
                        dpcd_val |= DP_PSR_CRC_VERIFICATION;
        }

        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, dpcd_val);

        drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
}

static u32 intel_psr1_get_tp_time(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 val = 0;

        if (INTEL_GEN(dev_priv) >= 11)
                val |= EDP_PSR_TP4_TIME_0US;

        if (dev_priv->vbt.psr.tp1_wakeup_time_us == 0)
                val |= EDP_PSR_TP1_TIME_0us;
        else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 100)
                val |= EDP_PSR_TP1_TIME_100us;
        else if (dev_priv->vbt.psr.tp1_wakeup_time_us <= 500)
                val |= EDP_PSR_TP1_TIME_500us;
        else
                val |= EDP_PSR_TP1_TIME_2500us;

        if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us == 0)
                val |= EDP_PSR_TP2_TP3_TIME_0us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 100)
                val |= EDP_PSR_TP2_TP3_TIME_100us;
        else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time_us <= 500)
                val |= EDP_PSR_TP2_TP3_TIME_500us;
        else
                val |= EDP_PSR_TP2_TP3_TIME_2500us;

        if (intel_dp_source_supports_hbr2(intel_dp) &&
            drm_dp_tps3_supported(intel_dp->dpcd))
                val |= EDP_PSR_TP1_TP3_SEL;
        else
                val |= EDP_PSR_TP1_TP2_SEL;

        return val;
}

static void hsw_activate_psr1(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 max_sleep_time = 0x1f;
        u32 val = EDP_PSR_ENABLE;

        /* Let's use 6 as the minimum to cover all known cases including the
         * off-by-one issue that HW has in some cases.
         */
        int idle_frames = max(6, dev_priv->vbt.psr.idle_frames);

        /* sink_sync_latency of 8 means source has to wait for more than 8
         * frames, we'll go with 9 frames for now
         */
        idle_frames = max(idle_frames, dev_priv->psr.sink_sync_latency + 1);
        val |= idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;

        val |= max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT;
        if (IS_HASWELL(dev_priv))
                val |= EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES;

        if (dev_priv->psr.link_standby)
                val |= EDP_PSR_LINK_STANDBY;

        val |= intel_psr1_get_tp_time(intel_dp);

        if (INTEL_GEN(dev_priv) >= 8)
                val |= EDP_PSR_CRC_ENABLE;

        val |= I915_READ(EDP_PSR_CTL) & EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK;
        I915_WRITE(EDP_PSR_CTL, val);
}

static void hsw_activate_psr2(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        u32 val;

        /* Let's use 6 as the minimum to cover all known cases including the
         * off-by-one issue that HW has in some cases.
         */
        int idle_frames = max(6, dev_priv->vbt.psr.idle_frames);

        idle_frames = max(idle_frames, dev_priv->psr.sink_sync_latency + 1);
        val = idle_frames << EDP_PSR2_IDLE_FRAME_SHIFT;

        val |= EDP_PSR2_ENABLE | EDP_SU_TRACK_ENABLE;
        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
                val |= EDP_Y_COORDINATE_ENABLE;

        val |= EDP_PSR2_FRAME_BEFORE_SU(dev_priv->psr.sink_sync_latency + 1);

        if (dev_priv->vbt.psr.psr2_tp2_tp3_wakeup_time_us >= 0 &&
            dev_priv->vbt.psr.psr2_tp2_tp3_wakeup_time_us <= 50)
                val |= EDP_PSR2_TP2_TIME_50us;
        else if (dev_priv->vbt.psr.psr2_tp2_tp3_wakeup_time_us <= 100)
                val |= EDP_PSR2_TP2_TIME_100us;
        else if (dev_priv->vbt.psr.psr2_tp2_tp3_wakeup_time_us <= 500)
                val |= EDP_PSR2_TP2_TIME_500us;
        else
                val |= EDP_PSR2_TP2_TIME_2500us;

        /*
         * PSR2 HW is incorrectly using EDP_PSR_TP1_TP3_SEL and BSpec is
         * recommending keep this bit unset while PSR2 is enabled.
         */
        I915_WRITE(EDP_PSR_CTL, 0);

        I915_WRITE(EDP_PSR2_CTL, val);
}

static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
                                    struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        int crtc_hdisplay = crtc_state->base.adjusted_mode.crtc_hdisplay;
        int crtc_vdisplay = crtc_state->base.adjusted_mode.crtc_vdisplay;
        int psr_max_h = 0, psr_max_v = 0;

        if (!dev_priv->psr.sink_psr2_support)
                return false;

        /*
         * DSC and PSR2 cannot be enabled simultaneously. If a requested
         * resolution requires DSC to be enabled, priority is given to DSC
         * over PSR2.
         */
        if (crtc_state->dsc_params.compression_enable) {
                DRM_DEBUG_KMS("PSR2 cannot be enabled since DSC is enabled\n");
                return false;
        }

        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
                psr_max_h = 4096;
                psr_max_v = 2304;
        } else if (IS_GEN(dev_priv, 9)) {
                psr_max_h = 3640;
                psr_max_v = 2304;
        }

        if (crtc_hdisplay > psr_max_h || crtc_vdisplay > psr_max_v) {
                DRM_DEBUG_KMS("PSR2 not enabled, resolution %dx%d > max supported %dx%d\n",
                              crtc_hdisplay, crtc_vdisplay,
                              psr_max_h, psr_max_v);
                return false;
        }

        /*
         * HW sends SU blocks of size four scan lines, which means the starting
         * X coordinate and Y granularity requirements will always be met. We
         * only need to validate the SU block width is a multiple of
         * x granularity.
         */
        if (crtc_hdisplay % dev_priv->psr.su_x_granularity) {
                DRM_DEBUG_KMS("PSR2 not enabled, hdisplay(%d) not multiple of %d\n",
                              crtc_hdisplay, dev_priv->psr.su_x_granularity);
                return false;
        }

        if (crtc_state->crc_enabled) {
                DRM_DEBUG_KMS("PSR2 not enabled because it would inhibit pipe CRC calculation\n");
                return false;
        }

        return true;
}

void intel_psr_compute_config(struct intel_dp *intel_dp,
                              struct intel_crtc_state *crtc_state)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        const struct drm_display_mode *adjusted_mode =
                &crtc_state->base.adjusted_mode;
        int psr_setup_time;

        if (!CAN_PSR(dev_priv))
                return;

        if (intel_dp != dev_priv->psr.dp)
                return;

        /*
         * HSW spec explicitly says PSR is tied to port A.
         * BDW+ platforms with DDI implementation of PSR have different
         * PSR registers per transcoder and we only implement transcoder EDP
         * ones. Since by Display design transcoder EDP is tied to port A
         * we can safely escape based on the port A.
         */
        if (dig_port->base.port != PORT_A) {
                DRM_DEBUG_KMS("PSR condition failed: Port not supported\n");
                return;
        }

        if (dev_priv->psr.sink_not_reliable) {
                DRM_DEBUG_KMS("PSR sink implementation is not reliable\n");
                return;
        }

        if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
                DRM_DEBUG_KMS("PSR condition failed: Interlaced mode enabled\n");
                return;
        }

        psr_setup_time = drm_dp_psr_setup_time(intel_dp->psr_dpcd);
        if (psr_setup_time < 0) {
                DRM_DEBUG_KMS("PSR condition failed: Invalid PSR setup time (0x%02x)\n",
                              intel_dp->psr_dpcd[1]);
                return;
        }

        if (intel_usecs_to_scanlines(adjusted_mode, psr_setup_time) >
            adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay - 1) {
                DRM_DEBUG_KMS("PSR condition failed: PSR setup time (%d us) too long\n",
                              psr_setup_time);
                return;
        }

        crtc_state->has_psr = true;
        crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp, crtc_state);
}

static void intel_psr_activate(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (INTEL_GEN(dev_priv) >= 9)
                WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
        WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
        WARN_ON(dev_priv->psr.active);
        lockdep_assert_held(&dev_priv->psr.lock);

        /* psr1 and psr2 are mutually exclusive.*/
        if (dev_priv->psr.psr2_enabled)
                hsw_activate_psr2(intel_dp);
        else
                hsw_activate_psr1(intel_dp);

        dev_priv->psr.active = true;
}

static i915_reg_t gen9_chicken_trans_reg(struct drm_i915_private *dev_priv,
                                         enum transcoder cpu_transcoder)
{
        static const i915_reg_t regs[] = {
                [TRANSCODER_A] = CHICKEN_TRANS_A,
                [TRANSCODER_B] = CHICKEN_TRANS_B,
                [TRANSCODER_C] = CHICKEN_TRANS_C,
                [TRANSCODER_EDP] = CHICKEN_TRANS_EDP,
        };

        WARN_ON(INTEL_GEN(dev_priv) < 9);

        if (WARN_ON(cpu_transcoder >= ARRAY_SIZE(regs) ||
                    !regs[cpu_transcoder].reg))
                cpu_transcoder = TRANSCODER_A;

        return regs[cpu_transcoder];
}

static void intel_psr_enable_source(struct intel_dp *intel_dp,
                                    const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
        u32 mask;

        /* Only HSW and BDW have PSR AUX registers that need to be setup. SKL+
         * use hardcoded values PSR AUX transactions
         */
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                hsw_psr_setup_aux(intel_dp);

        if (dev_priv->psr.psr2_enabled && (IS_GEN(dev_priv, 9) &&
                                           !IS_GEMINILAKE(dev_priv))) {
                i915_reg_t reg = gen9_chicken_trans_reg(dev_priv,
                                                        cpu_transcoder);
                u32 chicken = I915_READ(reg);

                chicken |= PSR2_VSC_ENABLE_PROG_HEADER |
                           PSR2_ADD_VERTICAL_LINE_COUNT;
                I915_WRITE(reg, chicken);
        }

        /*
         * Per Spec: Avoid continuous PSR exit by masking MEMUP and HPD also
         * mask LPSP to avoid dependency on other drivers that might block
         * runtime_pm besides preventing  other hw tracking issues now we
         * can rely on frontbuffer tracking.
         */
        mask = EDP_PSR_DEBUG_MASK_MEMUP |
               EDP_PSR_DEBUG_MASK_HPD |
               EDP_PSR_DEBUG_MASK_LPSP |
               EDP_PSR_DEBUG_MASK_MAX_SLEEP;

        if (INTEL_GEN(dev_priv) < 11)
                mask |= EDP_PSR_DEBUG_MASK_DISP_REG_WRITE;

        I915_WRITE(EDP_PSR_DEBUG, mask);
}

static void intel_psr_enable_locked(struct drm_i915_private *dev_priv,
                                    const struct intel_crtc_state *crtc_state)
{
        struct intel_dp *intel_dp = dev_priv->psr.dp;

        WARN_ON(dev_priv->psr.enabled);

        dev_priv->psr.psr2_enabled = intel_psr2_enabled(dev_priv, crtc_state);
        dev_priv->psr.busy_frontbuffer_bits = 0;
        dev_priv->psr.pipe = to_intel_crtc(crtc_state->base.crtc)->pipe;

        DRM_DEBUG_KMS("Enabling PSR%s\n",
                      dev_priv->psr.psr2_enabled ? "2" : "1");
        intel_psr_setup_vsc(intel_dp, crtc_state);
        intel_psr_enable_sink(intel_dp);
        intel_psr_enable_source(intel_dp, crtc_state);
        dev_priv->psr.enabled = true;

        intel_psr_activate(intel_dp);
}

/**
 * intel_psr_enable - Enable PSR
 * @intel_dp: Intel DP
 * @crtc_state: new CRTC state
 *
 * This function can only be called after the pipe is fully trained and enabled.
 */
void intel_psr_enable(struct intel_dp *intel_dp,
                      const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (!crtc_state->has_psr)
                return;

        if (WARN_ON(!CAN_PSR(dev_priv)))
                return;

        WARN_ON(dev_priv->drrs.dp);

        mutex_lock(&dev_priv->psr.lock);

        if (!psr_global_enabled(dev_priv->psr.debug)) {
                DRM_DEBUG_KMS("PSR disabled by flag\n");
                goto unlock;
        }

        intel_psr_enable_locked(dev_priv, crtc_state);

unlock:
        mutex_unlock(&dev_priv->psr.lock);
}

static void intel_psr_exit(struct drm_i915_private *dev_priv)
{
        u32 val;

        if (!dev_priv->psr.active) {
                if (INTEL_GEN(dev_priv) >= 9)
                        WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
                WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
                return;
        }

        if (dev_priv->psr.psr2_enabled) {
                val = I915_READ(EDP_PSR2_CTL);
                WARN_ON(!(val & EDP_PSR2_ENABLE));
                I915_WRITE(EDP_PSR2_CTL, val & ~EDP_PSR2_ENABLE);
        } else {
                val = I915_READ(EDP_PSR_CTL);
                WARN_ON(!(val & EDP_PSR_ENABLE));
                I915_WRITE(EDP_PSR_CTL, val & ~EDP_PSR_ENABLE);
        }
        dev_priv->psr.active = false;
}

static void intel_psr_disable_locked(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        i915_reg_t psr_status;
        u32 psr_status_mask;

        lockdep_assert_held(&dev_priv->psr.lock);

        if (!dev_priv->psr.enabled)
                return;

        DRM_DEBUG_KMS("Disabling PSR%s\n",
                      dev_priv->psr.psr2_enabled ? "2" : "1");

        intel_psr_exit(dev_priv);

        if (dev_priv->psr.psr2_enabled) {
                psr_status = EDP_PSR2_STATUS;
                psr_status_mask = EDP_PSR2_STATUS_STATE_MASK;
        } else {
                psr_status = EDP_PSR_STATUS;
                psr_status_mask = EDP_PSR_STATUS_STATE_MASK;
        }

        /* Wait till PSR is idle */
        if (intel_wait_for_register(&dev_priv->uncore,
                                    psr_status, psr_status_mask, 0, 2000))
                DRM_ERROR("Timed out waiting PSR idle state\n");

        /* Disable PSR on Sink */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);

        dev_priv->psr.enabled = false;
}

/**
 * intel_psr_disable - Disable PSR
 * @intel_dp: Intel DP
 * @old_crtc_state: old CRTC state
 *
 * This function needs to be called before disabling pipe.
 */
void intel_psr_disable(struct intel_dp *intel_dp,
                       const struct intel_crtc_state *old_crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);

        if (!old_crtc_state->has_psr)
                return;

        if (WARN_ON(!CAN_PSR(dev_priv)))
                return;

        mutex_lock(&dev_priv->psr.lock);

        intel_psr_disable_locked(intel_dp);

        mutex_unlock(&dev_priv->psr.lock);
        cancel_work_sync(&dev_priv->psr.work);
}

static void psr_force_hw_tracking_exit(struct drm_i915_private *dev_priv)
{
        if (INTEL_GEN(dev_priv) >= 9)
                /*
                 * Display WA #0884: skl+
                 * This documented WA for bxt can be safely applied
                 * broadly so we can force HW tracking to exit PSR
                 * instead of disabling and re-enabling.
                 * Workaround tells us to write 0 to CUR_SURFLIVE_A,
                 * but it makes more sense write to the current active
                 * pipe.
                 */
                I915_WRITE(CURSURFLIVE(dev_priv->psr.pipe), 0);
        else
                /*
                 * A write to CURSURFLIVE do not cause HW tracking to exit PSR
                 * on older gens so doing the manual exit instead.
                 */
                intel_psr_exit(dev_priv);
}

/**
 * intel_psr_update - Update PSR state
 * @intel_dp: Intel DP
 * @crtc_state: new CRTC state
 *
 * This functions will update PSR states, disabling, enabling or switching PSR
 * version when executing fastsets. For full modeset, intel_psr_disable() and
 * intel_psr_enable() should be called instead.
 */
void intel_psr_update(struct intel_dp *intel_dp,
                      const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct i915_psr *psr = &dev_priv->psr;
        bool enable, psr2_enable;

        if (!CAN_PSR(dev_priv) || READ_ONCE(psr->dp) != intel_dp)
                return;

        mutex_lock(&dev_priv->psr.lock);

        enable = crtc_state->has_psr && psr_global_enabled(psr->debug);
        psr2_enable = intel_psr2_enabled(dev_priv, crtc_state);

        if (enable == psr->enabled && psr2_enable == psr->psr2_enabled) {
                /* Force a PSR exit when enabling CRC to avoid CRC timeouts */
                if (crtc_state->crc_enabled && psr->enabled)
                        psr_force_hw_tracking_exit(dev_priv);
                else if (INTEL_GEN(dev_priv) < 9 && psr->enabled) {
                        /*
                         * Activate PSR again after a force exit when enabling
                         * CRC in older gens
                         */
                        if (!dev_priv->psr.active &&
                            !dev_priv->psr.busy_frontbuffer_bits)
                                schedule_work(&dev_priv->psr.work);
                }

                goto unlock;
        }

        if (psr->enabled)
                intel_psr_disable_locked(intel_dp);

        if (enable)
                intel_psr_enable_locked(dev_priv, crtc_state);

unlock:
        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_wait_for_idle - wait for PSR1 to idle
 * @new_crtc_state: new CRTC state
 * @out_value: PSR status in case of failure
 *
 * This function is expected to be called from pipe_update_start() where it is
 * not expected to race with PSR enable or disable.
 *
 * Returns: 0 on success or -ETIMEOUT if PSR status does not idle.
 */
int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state,
                            u32 *out_value)
{
        struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);

        if (!dev_priv->psr.enabled || !new_crtc_state->has_psr)
                return 0;

        /* FIXME: Update this for PSR2 if we need to wait for idle */
        if (READ_ONCE(dev_priv->psr.psr2_enabled))
                return 0;

        /*
         * From bspec: Panel Self Refresh (BDW+)
         * Max. time for PSR to idle = Inverse of the refresh rate + 6 ms of
         * exit training time + 1.5 ms of aux channel handshake. 50 ms is
         * defensive enough to cover everything.
         */

        return __intel_wait_for_register(&dev_priv->uncore, EDP_PSR_STATUS,
                                         EDP_PSR_STATUS_STATE_MASK,
                                         EDP_PSR_STATUS_STATE_IDLE, 2, 50,
                                         out_value);
}

static bool __psr_wait_for_idle_locked(struct drm_i915_private *dev_priv)
{
        i915_reg_t reg;
        u32 mask;
        int err;

        if (!dev_priv->psr.enabled)
                return false;

        if (dev_priv->psr.psr2_enabled) {
                reg = EDP_PSR2_STATUS;
                mask = EDP_PSR2_STATUS_STATE_MASK;
        } else {
                reg = EDP_PSR_STATUS;
                mask = EDP_PSR_STATUS_STATE_MASK;
        }

        mutex_unlock(&dev_priv->psr.lock);

        err = intel_wait_for_register(&dev_priv->uncore, reg, mask, 0, 50);
        if (err)
                DRM_ERROR("Timed out waiting for PSR Idle for re-enable\n");

        /* After the unlocked wait, verify that PSR is still wanted! */
        mutex_lock(&dev_priv->psr.lock);
        return err == 0 && dev_priv->psr.enabled;
}

static int intel_psr_fastset_force(struct drm_i915_private *dev_priv)

{
        struct drm_device *dev = &dev_priv->drm;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_atomic_state *state;
        struct drm_crtc *crtc;
        int err;

        state = drm_atomic_state_alloc(dev);
        if (!state)
                return -ENOMEM;

        drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
        state->acquire_ctx = &ctx;

retry:
        drm_for_each_crtc(crtc, dev) {
                struct drm_crtc_state *crtc_state;
                struct intel_crtc_state *intel_crtc_state;

                crtc_state = drm_atomic_get_crtc_state(state, crtc);
                if (IS_ERR(crtc_state)) {
                        err = PTR_ERR(crtc_state);
                        goto error;
                }

                intel_crtc_state = to_intel_crtc_state(crtc_state);

                if (crtc_state->active && intel_crtc_state->has_psr) {
                        /* Mark mode as changed to trigger a pipe->update() */
                        crtc_state->mode_changed = true;
                        break;
                }
        }

        err = drm_atomic_commit(state);

error:
        if (err == -EDEADLK) {
                drm_atomic_state_clear(state);
                err = drm_modeset_backoff(&ctx);
                if (!err)
                        goto retry;
        }

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);
        drm_atomic_state_put(state);

        return err;
}

int intel_psr_debug_set(struct drm_i915_private *dev_priv, u64 val)
{
        const u32 mode = val & I915_PSR_DEBUG_MODE_MASK;
        u32 old_mode;
        int ret;

        if (val & ~(I915_PSR_DEBUG_IRQ | I915_PSR_DEBUG_MODE_MASK) ||
            mode > I915_PSR_DEBUG_FORCE_PSR1) {
                DRM_DEBUG_KMS("Invalid debug mask %llx\n", val);
                return -EINVAL;
        }

        ret = mutex_lock_interruptible(&dev_priv->psr.lock);
        if (ret)
                return ret;

        old_mode = dev_priv->psr.debug & I915_PSR_DEBUG_MODE_MASK;
        dev_priv->psr.debug = val;
        intel_psr_irq_control(dev_priv, dev_priv->psr.debug);

        mutex_unlock(&dev_priv->psr.lock);

        if (old_mode != mode)
                ret = intel_psr_fastset_force(dev_priv);

        return ret;
}

static void intel_psr_handle_irq(struct drm_i915_private *dev_priv)
{
        struct i915_psr *psr = &dev_priv->psr;

        intel_psr_disable_locked(psr->dp);
        psr->sink_not_reliable = true;
        /* let's make sure that sink is awaken */
        drm_dp_dpcd_writeb(&psr->dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
}

static void intel_psr_work(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, typeof(*dev_priv), psr.work);

        mutex_lock(&dev_priv->psr.lock);

        if (!dev_priv->psr.enabled)
                goto unlock;

        if (READ_ONCE(dev_priv->psr.irq_aux_error))
                intel_psr_handle_irq(dev_priv);

        /*
         * We have to make sure PSR is ready for re-enable
         * otherwise it keeps disabled until next full enable/disable cycle.
         * PSR might take some time to get fully disabled
         * and be ready for re-enable.
         */
        if (!__psr_wait_for_idle_locked(dev_priv))
                goto unlock;

        /*
         * The delayed work can race with an invalidate hence we need to
         * recheck. Since psr_flush first clears this and then reschedules we
         * won't ever miss a flush when bailing out here.
         */
        if (dev_priv->psr.busy_frontbuffer_bits || dev_priv->psr.active)
                goto unlock;

        intel_psr_activate(dev_priv->psr.dp);
unlock:
        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_invalidate - Invalidade PSR
 * @dev_priv: i915 device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 * @origin: which operation caused the invalidate
 *
 * Since the hardware frontbuffer tracking has gaps we need to integrate
 * with the software frontbuffer tracking. This function gets called every
 * time frontbuffer rendering starts and a buffer gets dirtied. PSR must be
 * disabled if the frontbuffer mask contains a buffer relevant to PSR.
 *
 * Dirty frontbuffers relevant to PSR are tracked in busy_frontbuffer_bits."
 */
void intel_psr_invalidate(struct drm_i915_private *dev_priv,
                          unsigned frontbuffer_bits, enum fb_op_origin origin)
{
        if (!CAN_PSR(dev_priv))
                return;

        if (origin == ORIGIN_FLIP)
                return;

        mutex_lock(&dev_priv->psr.lock);
        if (!dev_priv->psr.enabled) {
                mutex_unlock(&dev_priv->psr.lock);
                return;
        }

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(dev_priv->psr.pipe);
        dev_priv->psr.busy_frontbuffer_bits |= frontbuffer_bits;

        if (frontbuffer_bits)
                intel_psr_exit(dev_priv);

        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_flush - Flush PSR
 * @dev_priv: i915 device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 * @origin: which operation caused the flush
 *
 * Since the hardware frontbuffer tracking has gaps we need to integrate
 * with the software frontbuffer tracking. This function gets called every
 * time frontbuffer rendering has completed and flushed out to memory. PSR
 * can be enabled again if no other frontbuffer relevant to PSR is dirty.
 *
 * Dirty frontbuffers relevant to PSR are tracked in busy_frontbuffer_bits.
 */
void intel_psr_flush(struct drm_i915_private *dev_priv,
                     unsigned frontbuffer_bits, enum fb_op_origin origin)
{
        if (!CAN_PSR(dev_priv))
                return;

        if (origin == ORIGIN_FLIP)
                return;

        mutex_lock(&dev_priv->psr.lock);
        if (!dev_priv->psr.enabled) {
                mutex_unlock(&dev_priv->psr.lock);
                return;
        }

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(dev_priv->psr.pipe);
        dev_priv->psr.busy_frontbuffer_bits &= ~frontbuffer_bits;

        /* By definition flush = invalidate + flush */
        if (frontbuffer_bits)
                psr_force_hw_tracking_exit(dev_priv);

        if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits)
                schedule_work(&dev_priv->psr.work);
        mutex_unlock(&dev_priv->psr.lock);
}

/**
 * intel_psr_init - Init basic PSR work and mutex.
 * @dev_priv: i915 device private
 *
 * This function is  called only once at driver load to initialize basic
 * PSR stuff.
 */
void intel_psr_init(struct drm_i915_private *dev_priv)
{
        u32 val;

        if (!HAS_PSR(dev_priv))
                return;

        dev_priv->psr_mmio_base = IS_HASWELL(dev_priv) ?
                HSW_EDP_PSR_BASE : BDW_EDP_PSR_BASE;

        if (!dev_priv->psr.sink_support)
                return;

        if (i915_modparams.enable_psr == -1)
                if (INTEL_GEN(dev_priv) < 9 || !dev_priv->vbt.psr.enable)
                        i915_modparams.enable_psr = 0;

        /*
         * If a PSR error happened and the driver is reloaded, the EDP_PSR_IIR
         * will still keep the error set even after the reset done in the
         * irq_preinstall and irq_uninstall hooks.
         * And enabling in this situation cause the screen to freeze in the
         * first time that PSR HW tries to activate so lets keep PSR disabled
         * to avoid any rendering problems.
         */
        val = I915_READ(EDP_PSR_IIR);
        val &= EDP_PSR_ERROR(edp_psr_shift(TRANSCODER_EDP));
        if (val) {
                DRM_DEBUG_KMS("PSR interruption error set\n");
                dev_priv->psr.sink_not_reliable = true;
        }

        /* Set link_standby x link_off defaults */
        if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
                /* HSW and BDW require workarounds that we don't implement. */
                dev_priv->psr.link_standby = false;
        else
                /* For new platforms let's respect VBT back again */
                dev_priv->psr.link_standby = dev_priv->vbt.psr.full_link;

        INIT_WORK(&dev_priv->psr.work, intel_psr_work);
        mutex_init(&dev_priv->psr.lock);
}

void intel_psr_short_pulse(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        struct i915_psr *psr = &dev_priv->psr;
        u8 val;
        const u8 errors = DP_PSR_RFB_STORAGE_ERROR |
                          DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR |
                          DP_PSR_LINK_CRC_ERROR;

        if (!CAN_PSR(dev_priv) || !intel_dp_is_edp(intel_dp))
                return;

        mutex_lock(&psr->lock);

        if (!psr->enabled || psr->dp != intel_dp)
                goto exit;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS, &val) != 1) {
                DRM_ERROR("PSR_STATUS dpcd read failed\n");
                goto exit;
        }

        if ((val & DP_PSR_SINK_STATE_MASK) == DP_PSR_SINK_INTERNAL_ERROR) {
                DRM_DEBUG_KMS("PSR sink internal error, disabling PSR\n");
                intel_psr_disable_locked(intel_dp);
                psr->sink_not_reliable = true;
        }

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_ERROR_STATUS, &val) != 1) {
                DRM_ERROR("PSR_ERROR_STATUS dpcd read failed\n");
                goto exit;
        }

        if (val & DP_PSR_RFB_STORAGE_ERROR)
                DRM_DEBUG_KMS("PSR RFB storage error, disabling PSR\n");
        if (val & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
                DRM_DEBUG_KMS("PSR VSC SDP uncorrectable error, disabling PSR\n");
        if (val & DP_PSR_LINK_CRC_ERROR)
                DRM_ERROR("PSR Link CRC error, disabling PSR\n");

        if (val & ~errors)
                DRM_ERROR("PSR_ERROR_STATUS unhandled errors %x\n",
                          val & ~errors);
        if (val & errors) {
                intel_psr_disable_locked(intel_dp);
                psr->sink_not_reliable = true;
        }
        /* clear status register */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS, val);
exit:
        mutex_unlock(&psr->lock);
}

bool intel_psr_enabled(struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
        bool ret;

        if (!CAN_PSR(dev_priv) || !intel_dp_is_edp(intel_dp))
                return false;

        mutex_lock(&dev_priv->psr.lock);
        ret = (dev_priv->psr.dp == intel_dp && dev_priv->psr.enabled);
        mutex_unlock(&dev_priv->psr.lock);

        return ret;
}