// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2015 MediaTek Inc.
 * Author:
 *  Zhigang.Wei <zhigang.wei@mediatek.com>
 *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "xhci.h"
#include "xhci-mtk.h"

#define SSP_BW_BOUNDARY 130000
#define SS_BW_BOUNDARY  51000
/* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
#define HS_BW_BOUNDARY  6144
/* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
#define FS_PAYLOAD_MAX 188
/*
 * max number of microframes for split transfer,
 * for fs isoc in : 1 ss + 1 idle + 7 cs
 */
#define TT_MICROFRAMES_MAX 9

/* mtk scheduler bitmasks */
#define EP_BPKTS(p)     ((p) & 0x7f)
#define EP_BCSCOUNT(p)  (((p) & 0x7) << 8)
#define EP_BBM(p)       ((p) << 11)
#define EP_BOFFSET(p)   ((p) & 0x3fff)
#define EP_BREPEAT(p)   (((p) & 0x7fff) << 16)

static int is_fs_or_ls(enum usb_device_speed speed)
{
        return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
}

/*
* get the index of bandwidth domains array which @ep belongs to.
*
* the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
* each HS root port is treated as a single bandwidth domain,
* but each SS root port is treated as two bandwidth domains, one for IN eps,
* one for OUT eps.
* @real_port value is defined as follow according to xHCI spec:
* 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
* so the bandwidth domain array is organized as follow for simplification:
* SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
*/
static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
        struct usb_host_endpoint *ep)
{
        struct xhci_virt_device *virt_dev;
        int bw_index;

        virt_dev = xhci->devs[udev->slot_id];

        if (udev->speed >= USB_SPEED_SUPER) {
                if (usb_endpoint_dir_out(&ep->desc))
                        bw_index = (virt_dev->real_port - 1) * 2;
                else
                        bw_index = (virt_dev->real_port - 1) * 2 + 1;
        } else {
                /* add one more for each SS port */
                bw_index = virt_dev->real_port + xhci->usb3_rhub.num_ports - 1;
        }

        return bw_index;
}

static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
{
        u32 esit;

        esit = 1 << CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
        if (esit > XHCI_MTK_MAX_ESIT)
                esit = XHCI_MTK_MAX_ESIT;

        return esit;
}

static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
{
        struct usb_tt *utt = udev->tt;
        struct mu3h_sch_tt *tt, **tt_index, **ptt;
        unsigned int port;
        bool allocated_index = false;

        if (!utt)
                return NULL;    /* Not below a TT */

        /*
         * Find/create our data structure.
         * For hubs with a single TT, we get it directly.
         * For hubs with multiple TTs, there's an extra level of pointers.
         */
        tt_index = NULL;
        if (utt->multi) {
                tt_index = utt->hcpriv;
                if (!tt_index) {        /* Create the index array */
                        tt_index = kcalloc(utt->hub->maxchild,
                                        sizeof(*tt_index), GFP_KERNEL);
                        if (!tt_index)
                                return ERR_PTR(-ENOMEM);
                        utt->hcpriv = tt_index;
                        allocated_index = true;
                }
                port = udev->ttport - 1;
                ptt = &tt_index[port];
        } else {
                port = 0;
                ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
        }

        tt = *ptt;
        if (!tt) {      /* Create the mu3h_sch_tt */
                tt = kzalloc(sizeof(*tt), GFP_KERNEL);
                if (!tt) {
                        if (allocated_index) {
                                utt->hcpriv = NULL;
                                kfree(tt_index);
                        }
                        return ERR_PTR(-ENOMEM);
                }
                INIT_LIST_HEAD(&tt->ep_list);
                tt->usb_tt = utt;
                tt->tt_port = port;
                *ptt = tt;
        }

        return tt;
}

/* Release the TT above udev, if it's not in use */
static void drop_tt(struct usb_device *udev)
{
        struct usb_tt *utt = udev->tt;
        struct mu3h_sch_tt *tt, **tt_index, **ptt;
        int i, cnt;

        if (!utt || !utt->hcpriv)
                return;         /* Not below a TT, or never allocated */

        cnt = 0;
        if (utt->multi) {
                tt_index = utt->hcpriv;
                ptt = &tt_index[udev->ttport - 1];
                /*  How many entries are left in tt_index? */
                for (i = 0; i < utt->hub->maxchild; ++i)
                        cnt += !!tt_index[i];
        } else {
                tt_index = NULL;
                ptt = (struct mu3h_sch_tt **)&utt->hcpriv;
        }

        tt = *ptt;
        if (!tt || !list_empty(&tt->ep_list))
                return;         /* never allocated , or still in use*/

        *ptt = NULL;
        kfree(tt);

        if (cnt == 1) {
                utt->hcpriv = NULL;
                kfree(tt_index);
        }
}

static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
        struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
{
        struct mu3h_sch_ep_info *sch_ep;
        struct mu3h_sch_tt *tt = NULL;
        u32 len_bw_budget_table;
        size_t mem_size;

        if (is_fs_or_ls(udev->speed))
                len_bw_budget_table = TT_MICROFRAMES_MAX;
        else if ((udev->speed >= USB_SPEED_SUPER)
                        && usb_endpoint_xfer_isoc(&ep->desc))
                len_bw_budget_table = get_esit(ep_ctx);
        else
                len_bw_budget_table = 1;

        mem_size = sizeof(struct mu3h_sch_ep_info) +
                        len_bw_budget_table * sizeof(u32);
        sch_ep = kzalloc(mem_size, GFP_KERNEL);
        if (!sch_ep)
                return ERR_PTR(-ENOMEM);

        if (is_fs_or_ls(udev->speed)) {
                tt = find_tt(udev);
                if (IS_ERR(tt)) {
                        kfree(sch_ep);
                        return ERR_PTR(-ENOMEM);
                }
        }

        sch_ep->sch_tt = tt;
        sch_ep->ep = ep;

        return sch_ep;
}

static void setup_sch_info(struct usb_device *udev,
                struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
{
        u32 ep_type;
        u32 maxpkt;
        u32 max_burst;
        u32 mult;
        u32 esit_pkts;
        u32 max_esit_payload;
        u32 *bwb_table = sch_ep->bw_budget_table;
        int i;

        ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
        maxpkt = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
        max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
        mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
        max_esit_payload =
                (CTX_TO_MAX_ESIT_PAYLOAD_HI(
                        le32_to_cpu(ep_ctx->ep_info)) << 16) |
                 CTX_TO_MAX_ESIT_PAYLOAD(le32_to_cpu(ep_ctx->tx_info));

        sch_ep->esit = get_esit(ep_ctx);
        sch_ep->ep_type = ep_type;
        sch_ep->maxpkt = maxpkt;
        sch_ep->offset = 0;
        sch_ep->burst_mode = 0;
        sch_ep->repeat = 0;

        if (udev->speed == USB_SPEED_HIGH) {
                sch_ep->cs_count = 0;

                /*
                 * usb_20 spec section5.9
                 * a single microframe is enough for HS synchromous endpoints
                 * in a interval
                 */
                sch_ep->num_budget_microframes = 1;

                /*
                 * xHCI spec section6.2.3.4
                 * @max_burst is the number of additional transactions
                 * opportunities per microframe
                 */
                sch_ep->pkts = max_burst + 1;
                sch_ep->bw_cost_per_microframe = maxpkt * sch_ep->pkts;
                bwb_table[0] = sch_ep->bw_cost_per_microframe;
        } else if (udev->speed >= USB_SPEED_SUPER) {
                /* usb3_r1 spec section4.4.7 & 4.4.8 */
                sch_ep->cs_count = 0;
                sch_ep->burst_mode = 1;
                /*
                 * some device's (d)wBytesPerInterval is set as 0,
                 * then max_esit_payload is 0, so evaluate esit_pkts from
                 * mult and burst
                 */
                esit_pkts = DIV_ROUND_UP(max_esit_payload, maxpkt);
                if (esit_pkts == 0)
                        esit_pkts = (mult + 1) * (max_burst + 1);

                if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
                        sch_ep->pkts = esit_pkts;
                        sch_ep->num_budget_microframes = 1;
                        bwb_table[0] = maxpkt * sch_ep->pkts;
                }

                if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
                        u32 remainder;

                        if (sch_ep->esit == 1)
                                sch_ep->pkts = esit_pkts;
                        else if (esit_pkts <= sch_ep->esit)
                                sch_ep->pkts = 1;
                        else
                                sch_ep->pkts = roundup_pow_of_two(esit_pkts)
                                        / sch_ep->esit;

                        sch_ep->num_budget_microframes =
                                DIV_ROUND_UP(esit_pkts, sch_ep->pkts);

                        sch_ep->repeat = !!(sch_ep->num_budget_microframes > 1);
                        sch_ep->bw_cost_per_microframe = maxpkt * sch_ep->pkts;

                        remainder = sch_ep->bw_cost_per_microframe;
                        remainder *= sch_ep->num_budget_microframes;
                        remainder -= (maxpkt * esit_pkts);
                        for (i = 0; i < sch_ep->num_budget_microframes - 1; i++)
                                bwb_table[i] = sch_ep->bw_cost_per_microframe;

                        /* last one <= bw_cost_per_microframe */
                        bwb_table[i] = remainder;
                }
        } else if (is_fs_or_ls(udev->speed)) {
                sch_ep->pkts = 1; /* at most one packet for each microframe */

                /*
                 * num_budget_microframes and cs_count will be updated when
                 * check TT for INT_OUT_EP, ISOC/INT_IN_EP type
                 */
                sch_ep->cs_count = DIV_ROUND_UP(maxpkt, FS_PAYLOAD_MAX);
                sch_ep->num_budget_microframes = sch_ep->cs_count;
                sch_ep->bw_cost_per_microframe =
                        (maxpkt < FS_PAYLOAD_MAX) ? maxpkt : FS_PAYLOAD_MAX;

                /* init budget table */
                if (ep_type == ISOC_OUT_EP) {
                        for (i = 0; i < sch_ep->num_budget_microframes; i++)
                                bwb_table[i] =  sch_ep->bw_cost_per_microframe;
                } else if (ep_type == INT_OUT_EP) {
                        /* only first one consumes bandwidth, others as zero */
                        bwb_table[0] = sch_ep->bw_cost_per_microframe;
                } else { /* INT_IN_EP or ISOC_IN_EP */
                        bwb_table[0] = 0; /* start split */
                        bwb_table[1] = 0; /* idle */
                        /*
                         * due to cs_count will be updated according to cs
                         * position, assign all remainder budget array
                         * elements as @bw_cost_per_microframe, but only first
                         * @num_budget_microframes elements will be used later
                         */
                        for (i = 2; i < TT_MICROFRAMES_MAX; i++)
                                bwb_table[i] =  sch_ep->bw_cost_per_microframe;
                }
        }
}

/* Get maximum bandwidth when we schedule at offset slot. */
static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
        struct mu3h_sch_ep_info *sch_ep, u32 offset)
{
        u32 num_esit;
        u32 max_bw = 0;
        u32 bw;
        int i;
        int j;

        num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
        for (i = 0; i < num_esit; i++) {
                u32 base = offset + i * sch_ep->esit;

                for (j = 0; j < sch_ep->num_budget_microframes; j++) {
                        bw = sch_bw->bus_bw[base + j] +
                                        sch_ep->bw_budget_table[j];
                        if (bw > max_bw)
                                max_bw = bw;
                }
        }
        return max_bw;
}

static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
        struct mu3h_sch_ep_info *sch_ep, bool used)
{
        u32 num_esit;
        u32 base;
        int i;
        int j;

        num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
        for (i = 0; i < num_esit; i++) {
                base = sch_ep->offset + i * sch_ep->esit;
                for (j = 0; j < sch_ep->num_budget_microframes; j++) {
                        if (used)
                                sch_bw->bus_bw[base + j] +=
                                        sch_ep->bw_budget_table[j];
                        else
                                sch_bw->bus_bw[base + j] -=
                                        sch_ep->bw_budget_table[j];
                }
        }
}

static int check_sch_tt(struct usb_device *udev,
        struct mu3h_sch_ep_info *sch_ep, u32 offset)
{
        struct mu3h_sch_tt *tt = sch_ep->sch_tt;
        u32 extra_cs_count;
        u32 fs_budget_start;
        u32 start_ss, last_ss;
        u32 start_cs, last_cs;
        int i;

        start_ss = offset % 8;
        fs_budget_start = (start_ss + 1) % 8;

        if (sch_ep->ep_type == ISOC_OUT_EP) {
                last_ss = start_ss + sch_ep->cs_count - 1;

                /*
                 * usb_20 spec section11.18:
                 * must never schedule Start-Split in Y6
                 */
                if (!(start_ss == 7 || last_ss < 6))
                        return -ERANGE;

                for (i = 0; i < sch_ep->cs_count; i++)
                        if (test_bit(offset + i, tt->split_bit_map))
                                return -ERANGE;

        } else {
                u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);

                /*
                 * usb_20 spec section11.18:
                 * must never schedule Start-Split in Y6
                 */
                if (start_ss == 6)
                        return -ERANGE;

                /* one uframe for ss + one uframe for idle */
                start_cs = (start_ss + 2) % 8;
                last_cs = start_cs + cs_count - 1;

                if (last_cs > 7)
                        return -ERANGE;

                if (sch_ep->ep_type == ISOC_IN_EP)
                        extra_cs_count = (last_cs == 7) ? 1 : 2;
                else /*  ep_type : INTR IN / INTR OUT */
                        extra_cs_count = (fs_budget_start == 6) ? 1 : 2;

                cs_count += extra_cs_count;
                if (cs_count > 7)
                        cs_count = 7; /* HW limit */

                for (i = 0; i < cs_count + 2; i++) {
                        if (test_bit(offset + i, tt->split_bit_map))
                                return -ERANGE;
                }

                sch_ep->cs_count = cs_count;
                /* one for ss, the other for idle */
                sch_ep->num_budget_microframes = cs_count + 2;

                /*
                 * if interval=1, maxp >752, num_budge_micoframe is larger
                 * than sch_ep->esit, will overstep boundary
                 */
                if (sch_ep->num_budget_microframes > sch_ep->esit)
                        sch_ep->num_budget_microframes = sch_ep->esit;
        }

        return 0;
}

static void update_sch_tt(struct usb_device *udev,
        struct mu3h_sch_ep_info *sch_ep)
{
        struct mu3h_sch_tt *tt = sch_ep->sch_tt;
        u32 base, num_esit;
        int i, j;

        num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
        for (i = 0; i < num_esit; i++) {
                base = sch_ep->offset + i * sch_ep->esit;
                for (j = 0; j < sch_ep->num_budget_microframes; j++)
                        set_bit(base + j, tt->split_bit_map);
        }

        list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
}

static int check_sch_bw(struct usb_device *udev,
        struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
{
        u32 offset;
        u32 esit;
        u32 min_bw;
        u32 min_index;
        u32 worst_bw;
        u32 bw_boundary;
        u32 min_num_budget;
        u32 min_cs_count;
        bool tt_offset_ok = false;
        int ret;

        esit = sch_ep->esit;

        /*
         * Search through all possible schedule microframes.
         * and find a microframe where its worst bandwidth is minimum.
         */
        min_bw = ~0;
        min_index = 0;
        min_cs_count = sch_ep->cs_count;
        min_num_budget = sch_ep->num_budget_microframes;
        for (offset = 0; offset < esit; offset++) {
                if (is_fs_or_ls(udev->speed)) {
                        ret = check_sch_tt(udev, sch_ep, offset);
                        if (ret)
                                continue;
                        else
                                tt_offset_ok = true;
                }

                if ((offset + sch_ep->num_budget_microframes) > sch_ep->esit)
                        break;

                worst_bw = get_max_bw(sch_bw, sch_ep, offset);
                if (min_bw > worst_bw) {
                        min_bw = worst_bw;
                        min_index = offset;
                        min_cs_count = sch_ep->cs_count;
                        min_num_budget = sch_ep->num_budget_microframes;
                }
                if (min_bw == 0)
                        break;
        }

        if (udev->speed == USB_SPEED_SUPER_PLUS)
                bw_boundary = SSP_BW_BOUNDARY;
        else if (udev->speed == USB_SPEED_SUPER)
                bw_boundary = SS_BW_BOUNDARY;
        else
                bw_boundary = HS_BW_BOUNDARY;

        /* check bandwidth */
        if (min_bw > bw_boundary)
                return -ERANGE;

        sch_ep->offset = min_index;
        sch_ep->cs_count = min_cs_count;
        sch_ep->num_budget_microframes = min_num_budget;

        if (is_fs_or_ls(udev->speed)) {
                /* all offset for tt is not ok*/
                if (!tt_offset_ok)
                        return -ERANGE;

                update_sch_tt(udev, sch_ep);
        }

        /* update bus bandwidth info */
        update_bus_bw(sch_bw, sch_ep, 1);

        return 0;
}

static bool need_bw_sch(struct usb_host_endpoint *ep,
        enum usb_device_speed speed, int has_tt)
{
        /* only for periodic endpoints */
        if (usb_endpoint_xfer_control(&ep->desc)
                || usb_endpoint_xfer_bulk(&ep->desc))
                return false;

        /*
         * for LS & FS periodic endpoints which its device is not behind
         * a TT are also ignored, root-hub will schedule them directly,
         * but need set @bpkts field of endpoint context to 1.
         */
        if (is_fs_or_ls(speed) && !has_tt)
                return false;

        return true;
}

int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
{
        struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
        struct mu3h_sch_bw_info *sch_array;
        int num_usb_bus;
        int i;

        /* ss IN and OUT are separated */
        num_usb_bus = xhci->usb3_rhub.num_ports * 2 + xhci->usb2_rhub.num_ports;

        sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
        if (sch_array == NULL)
                return -ENOMEM;

        for (i = 0; i < num_usb_bus; i++)
                INIT_LIST_HEAD(&sch_array[i].bw_ep_list);

        mtk->sch_array = sch_array;

        return 0;
}
EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);

void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
{
        kfree(mtk->sch_array);
}
EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);

int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
                struct usb_host_endpoint *ep)
{
        struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
        struct xhci_hcd *xhci;
        struct xhci_ep_ctx *ep_ctx;
        struct xhci_slot_ctx *slot_ctx;
        struct xhci_virt_device *virt_dev;
        struct mu3h_sch_bw_info *sch_bw;
        struct mu3h_sch_ep_info *sch_ep;
        struct mu3h_sch_bw_info *sch_array;
        unsigned int ep_index;
        int bw_index;
        int ret = 0;

        xhci = hcd_to_xhci(hcd);
        virt_dev = xhci->devs[udev->slot_id];
        ep_index = xhci_get_endpoint_index(&ep->desc);
        slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
        ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
        sch_array = mtk->sch_array;

        xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
                __func__, usb_endpoint_type(&ep->desc), udev->speed,
                usb_endpoint_maxp(&ep->desc),
                usb_endpoint_dir_in(&ep->desc), ep);

        if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
                /*
                 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
                 * device does not connected through an external HS hub
                 */
                if (usb_endpoint_xfer_int(&ep->desc)
                        || usb_endpoint_xfer_isoc(&ep->desc))
                        ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));

                return 0;
        }

        bw_index = get_bw_index(xhci, udev, ep);
        sch_bw = &sch_array[bw_index];

        sch_ep = create_sch_ep(udev, ep, ep_ctx);
        if (IS_ERR_OR_NULL(sch_ep))
                return -ENOMEM;

        setup_sch_info(udev, ep_ctx, sch_ep);

        ret = check_sch_bw(udev, sch_bw, sch_ep);
        if (ret) {
                xhci_err(xhci, "Not enough bandwidth!\n");
                if (is_fs_or_ls(udev->speed))
                        drop_tt(udev);

                kfree(sch_ep);
                return -ENOSPC;
        }

        list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);

        ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
                | EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
        ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
                | EP_BREPEAT(sch_ep->repeat));

        xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
                        sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
                        sch_ep->offset, sch_ep->repeat);

        return 0;
}
EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);

void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
                struct usb_host_endpoint *ep)
{
        struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
        struct xhci_hcd *xhci;
        struct xhci_slot_ctx *slot_ctx;
        struct xhci_virt_device *virt_dev;
        struct mu3h_sch_bw_info *sch_array;
        struct mu3h_sch_bw_info *sch_bw;
        struct mu3h_sch_ep_info *sch_ep;
        int bw_index;

        xhci = hcd_to_xhci(hcd);
        virt_dev = xhci->devs[udev->slot_id];
        slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
        sch_array = mtk->sch_array;

        xhci_dbg(xhci, "%s() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
                __func__, usb_endpoint_type(&ep->desc), udev->speed,
                usb_endpoint_maxp(&ep->desc),
                usb_endpoint_dir_in(&ep->desc), ep);

        if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
                return;

        bw_index = get_bw_index(xhci, udev, ep);
        sch_bw = &sch_array[bw_index];

        list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
                if (sch_ep->ep == ep) {
                        update_bus_bw(sch_bw, sch_ep, 0);
                        list_del(&sch_ep->endpoint);
                        if (is_fs_or_ls(udev->speed)) {
                                list_del(&sch_ep->tt_endpoint);
                                drop_tt(udev);
                        }
                        kfree(sch_ep);
                        break;
                }
        }
}
EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);