usb: xhci-mtk: get the microframe boundary for ESIT

Tune the boundary for FS/LS ESIT due to CS:
For ISOC out-ep, the controller starts transfer data after
the first SS; for others, the data is already transferred
before the last CS.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/49e5a269a47984f3126a70c3fb471b0c2874b8c2.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-mtk-sch.c

@@ -513,22 +513,35 @@ static void update_sch_tt(struct usb_device *udev,
 		list_del(&sch_ep->tt_endpoint);
 }
 
+static u32 get_esit_boundary(struct mu3h_sch_ep_info *sch_ep)
+{
+	u32 boundary = sch_ep->esit;
+
+	if (sch_ep->sch_tt) { /* LS/FS with TT */
+		/* tune for CS */
+		if (sch_ep->ep_type != ISOC_OUT_EP)
+			boundary++;
+		else if (boundary > 1) /* normally esit >= 8 for FS/LS */
+			boundary--;
+	}
+
+	return boundary;
+}
+
 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 esit_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.
@@ -537,7 +550,8 @@ 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++) {
+	esit_boundary = get_esit_boundary(sch_ep);
+	for (offset = 0; offset < sch_ep->esit; offset++) {
 		if (is_fs_or_ls(udev->speed)) {
 			ret = check_sch_tt(udev, sch_ep, offset);
 			if (ret)
@@ -546,7 +560,7 @@ static int check_sch_bw(struct usb_device *udev,
 				tt_offset_ok = true;
 		}
 
-		if ((offset + sch_ep->num_budget_microframes) > sch_ep->esit)
+		if ((offset + sch_ep->num_budget_microframes) > esit_boundary)
 			break;
 
 		worst_bw = get_max_bw(sch_bw, sch_ep, offset);