When the USB headset is plug into an external hub, sometimes
can't set config due to not enough bandwidth, so need improve
LS/FS INT/ISOC bandwidth scheduling with TT.

Fixes: 08e469de87a2 ("usb: xhci-mtk: supports bandwidth scheduling with 
multi-TT")
Signed-off-by: Yaqii Wu <[email protected]>
Signed-off-by: Chunfeng Yun <[email protected]>
---
 drivers/usb/host/xhci-mtk-sch.c | 270 +++++++++++++++++++++++---------
 drivers/usb/host/xhci-mtk.h     |   8 +-
 2 files changed, 201 insertions(+), 77 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index b45e5bf08997..f3cdfcf4e5bf 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -32,6 +32,35 @@
 #define EP_BOFFSET(p)  ((p) & 0x3fff)
 #define EP_BREPEAT(p)  (((p) & 0x7fff) << 16)
 
+enum mtk_sch_err_type {
+       SCH_SUCCESS = 0,
+       SCH_ERR_Y6,
+       SCH_SS_OVERLAP,
+       SCH_CS_OVERFLOW,
+       SCH_BW_OVERFLOW,
+       SCH_FIXME,
+};
+
+static char *sch_error_string(enum mtk_sch_err_type error)
+{
+       switch (error) {
+       case SCH_SUCCESS:
+               return "Success";
+       case SCH_ERR_Y6:
+               return "Can't schedule Start-Split in Y6";
+       case SCH_SS_OVERLAP:
+               return "Can't find a suitable Start-Split location";
+       case SCH_CS_OVERFLOW:
+               return "The last Complete-Split is greater than 7";
+       case SCH_BW_OVERFLOW:
+               return "Bandwidth exceeds the max limit";
+       case SCH_FIXME:
+               return "FIXME, to be resolved";
+       default:
+               return "Unknown error type";
+       }
+}
+
 static int is_fs_or_ls(enum usb_device_speed speed)
 {
        return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
@@ -81,11 +110,22 @@ static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
        return esit;
 }
 
+static u32 get_bw_boundary(enum usb_device_speed speed)
+{
+       switch (speed) {
+       case USB_SPEED_SUPER_PLUS:
+               return SSP_BW_BOUNDARY;
+       case USB_SPEED_SUPER:
+               return SS_BW_BOUNDARY;
+       default:
+               return HS_BW_BOUNDARY;
+       }
+}
+
 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)
@@ -107,10 +147,9 @@ static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
                        utt->hcpriv = tt_index;
                        allocated_index = true;
                }
-               port = udev->ttport - 1;
-               ptt = &tt_index[port];
+
+               ptt = &tt_index[udev->ttport - 1];
        } else {
-               port = 0;
                ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
        }
 
@@ -125,8 +164,7 @@ static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
                        return ERR_PTR(-ENOMEM);
                }
                INIT_LIST_HEAD(&tt->ep_list);
-               tt->usb_tt = utt;
-               tt->tt_port = port;
+
                *ptt = tt;
        }
 
@@ -206,6 +244,15 @@ static struct mu3h_sch_ep_info *create_sch_ep(struct 
usb_device *udev,
        return sch_ep;
 }
 
+static void delete_sch_ep(struct usb_device *udev, struct mu3h_sch_ep_info 
*sch_ep)
+{
+       if (sch_ep->sch_tt)
+               drop_tt(udev);
+
+       list_del(&sch_ep->endpoint);
+       kfree(sch_ep);
+}
+
 static void setup_sch_info(struct usb_device *udev,
                struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
 {
@@ -375,21 +422,55 @@ static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
                                        sch_ep->bw_budget_table[j];
                }
        }
-       sch_ep->allocated = used;
 }
 
-static int check_sch_tt(struct usb_device *udev,
-       struct mu3h_sch_ep_info *sch_ep, u32 offset)
+static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+       struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+       u32 num_esit, base;
+       u32 i, j;
+       u32 tmp;
+
+       num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+
+       for (i = 0; i < num_esit; i++) {
+               base = offset + i * sch_ep->esit;
+
+               /*
+                * Compared with hs bus, no matter what ep type
+                * The hub will always delay one uframe to send
+                * data for us. As described in the figure below.
+                */
+               if (sch_ep->ep_type == ISOC_OUT_EP) {
+                       for (j = 0; j < sch_ep->num_budget_microframes; j++) {
+                               tmp = tt->fs_bus_bw[base + 1 + j]
+                                       + sch_ep->bw_cost_per_microframe;
+
+                               if (tmp > FS_PAYLOAD_MAX)
+                                       return SCH_BW_OVERFLOW;
+                       }
+               } else {
+                       for (j = 0; j < sch_ep->cs_count; j++) {
+                               tmp = tt->fs_bus_bw[base + 1 + j]
+                                       + sch_ep->bw_cost_per_microframe;
+
+                               if (tmp > FS_PAYLOAD_MAX)
+                                       return SCH_BW_OVERFLOW;
+                       }
+               }
+       }
+       return SCH_SUCCESS;
+}
+
+static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, int 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;
+       u32 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;
@@ -399,12 +480,12 @@ static int check_sch_tt(struct usb_device *udev,
                 * 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;
+                       return SCH_ERR_Y6;
 
+               for (i = 0; i < sch_ep->cs_count; i++) {
+                       if (test_bit(offset + i, tt->ss_bit_map))
+                               return SCH_SS_OVERLAP;
+               }
        } else {
                u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
 
@@ -413,27 +494,36 @@ static int check_sch_tt(struct usb_device *udev,
                 * must never schedule Start-Split in Y6
                 */
                if (start_ss == 6)
-                       return -ERANGE;
+                       return SCH_ERR_Y6;
 
                /* 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;
+                       return SCH_CS_OVERFLOW;
 
+               /*
+                * usb_20 spec section11.18, the bottom of page 378:
+                * For interrupt endpoints, the maximum size of the LS/FS
+                * transaction guarantees that it can never require more than
+                * two complete-split transactions.
+                */
                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;
+                       extra_cs_count = 1;
 
                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;
+               if (test_bit(offset, tt->ss_bit_map))
+                       return SCH_SS_OVERLAP;
+
+               if (sch_ep->ep_type == INT_OUT_EP) {
+                       if (test_bit(offset, tt->idle_bit_map))
+                               return SCH_FIXME;
                }
 
                sch_ep->cs_count = cs_count;
@@ -448,41 +538,88 @@ static int check_sch_tt(struct usb_device *udev,
                        sch_ep->num_budget_microframes = sch_ep->esit;
        }
 
-       return 0;
+       return check_fs_bus_bw(sch_ep, offset);
 }
 
-static void update_sch_tt(struct usb_device *udev,
-       struct mu3h_sch_ep_info *sch_ep)
+static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
 {
        struct mu3h_sch_tt *tt = sch_ep->sch_tt;
        u32 base, num_esit;
-       int i, j;
+       u32 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);
+
+               if (sch_ep->ep_type == ISOC_OUT_EP) {
+                       for (j = 0; j < sch_ep->num_budget_microframes; j++) {
+                               if (used) {
+                                       set_bit(base + j, tt->ss_bit_map);
+                                       tt->fs_bus_bw[base + 1 + j] +=
+                                               sch_ep->bw_cost_per_microframe;
+                               } else {
+                                       clear_bit(base + j, tt->ss_bit_map);
+                                       tt->fs_bus_bw[base + 1 + j] -=
+                                               sch_ep->bw_cost_per_microframe;
+                               }
+                       }
+               } else {
+                       if (used)
+                               set_bit(base, tt->ss_bit_map);
+                       else
+                               clear_bit(base, tt->ss_bit_map);
+
+                       if (sch_ep->ep_type == INT_OUT_EP) {
+                               if (used)
+                                       set_bit(base + 1, tt->idle_bit_map);
+                               else
+                                       clear_bit(base + 1, tt->idle_bit_map);
+                       }
+
+                       for (j = 0; j < sch_ep->cs_count; j++) {
+                               if (used)
+                                       tt->fs_bus_bw[base + 1 + j] +=
+                                               sch_ep->bw_cost_per_microframe;
+                               else
+                                       tt->fs_bus_bw[base + 1 + j] -=
+                                               sch_ep->bw_cost_per_microframe;
+                       }
+               }
+       }
+}
+
+static int load_ep_bw(struct mu3h_sch_bw_info *sch_bw,
+                     struct mu3h_sch_ep_info *sch_ep, bool loaded)
+{
+       struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+
+       if (sch_ep->sch_tt) {
+               update_sch_tt(sch_ep, loaded);
+               if (loaded)
+                       list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
+               else
+                       list_del(&sch_ep->tt_endpoint);
        }
 
-       list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
+       /* update bus bandwidth info */
+       update_bus_bw(sch_bw, sch_ep, loaded);
+       sch_ep->allocated = loaded;
+       return 0;
 }
 
 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 boundary;
        u32 min_num_budget;
        u32 min_cs_count;
-       bool tt_offset_ok = false;
-       int ret;
-
-       esit = sch_ep->esit;
+       int ret = 0;
 
        /*
         * Search through all possible schedule microframes.
@@ -492,16 +629,20 @@ static int check_sch_bw(struct usb_device *udev,
        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)
+
+       if (is_fs_or_ls(udev->speed) && sch_ep->ep_type != ISOC_OUT_EP)
+               boundary = sch_ep->esit + 1;
+       else
+               boundary = sch_ep->esit;
+
+       for (offset = 0; offset < sch_ep->esit; offset++) {
+               if (sch_ep->sch_tt) {
+                       ret = check_sch_tt(sch_ep, offset);
+                       if (ret != SCH_SUCCESS)
                                continue;
-                       else
-                               tt_offset_ok = true;
                }
 
-               if ((offset + sch_ep->num_budget_microframes) > sch_ep->esit)
+               if ((offset + sch_ep->num_budget_microframes) > boundary)
                        break;
 
                worst_bw = get_max_bw(sch_bw, sch_ep, offset);
@@ -515,33 +656,22 @@ static int check_sch_bw(struct usb_device *udev,
                        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;
-
+       bw_boundary = get_bw_boundary(udev->speed);
        /* check bandwidth */
-       if (min_bw > bw_boundary)
+       if (min_bw > bw_boundary) {
+               if (ret) {
+                       dev_err(&udev->dev, "%s %s\n", __func__,
+                               sch_error_string(ret));
+                       return -ret;
+               }
+
                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;
+       return load_ep_bw(sch_bw, sch_ep, true);
 }
 
 static void destroy_sch_ep(struct usb_device *udev,
@@ -549,23 +679,17 @@ static void destroy_sch_ep(struct usb_device *udev,
 {
        /* only release ep bw check passed by check_sch_bw() */
        if (sch_ep->allocated)
-               update_bus_bw(sch_bw, sch_ep, 0);
+               load_ep_bw(sch_bw, sch_ep, false);
 
-       list_del(&sch_ep->endpoint);
-
-       if (sch_ep->sch_tt) {
-               list_del(&sch_ep->tt_endpoint);
-               drop_tt(udev);
-       }
-       kfree(sch_ep);
+       delete_sch_ep(udev, sch_ep);
 }
 
 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))
+       if (usb_endpoint_xfer_control(&ep->desc) ||
+           usb_endpoint_xfer_bulk(&ep->desc))
                return false;
 
        /*
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index cbb09dfea62e..81e9b56958c5 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -26,10 +26,10 @@
  * @tt_port: TT port number
  */
 struct mu3h_sch_tt {
-       DECLARE_BITMAP(split_bit_map, XHCI_MTK_MAX_ESIT);
+       DECLARE_BITMAP(ss_bit_map, XHCI_MTK_MAX_ESIT);
+       DECLARE_BITMAP(idle_bit_map, XHCI_MTK_MAX_ESIT);
+       u32 fs_bus_bw[XHCI_MTK_MAX_ESIT + 1];
        struct list_head ep_list;
-       struct usb_tt *usb_tt;
-       int tt_port;
 };
 
 /**
@@ -84,9 +84,9 @@ struct mu3h_sch_ep_info {
        struct list_head endpoint;
        struct list_head tt_endpoint;
        struct mu3h_sch_tt *sch_tt;
+       struct usb_host_endpoint *ep;
        u32 ep_type;
        u32 maxpkt;
-       void *ep;
        bool allocated;
        /*
         * mtk xHCI scheduling information put into reserved DWs
-- 
2.18.0

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