usb: xhci-mtk: allow multiple Start-Split in a microframe

This patch is used to relax bandwidth schedule by allowing multiple
Start-Split in the same microframe.
Reviewed-and-Tested-by: Ikjoon Jang <ikjn@chromium.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1623995165-25759-1-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -470,11 +470,9 @@ static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
 
 static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
 {
-	struct mu3h_sch_tt *tt = sch_ep->sch_tt;
 	u32 extra_cs_count;
 	u32 start_ss, last_ss;
 	u32 start_cs, last_cs;
-	int i;
 
 	if (!sch_ep->sch_tt)
 		return 0;
@@ -491,10 +489,6 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
 		if (!(start_ss == 7 || last_ss < 6))
 			return -ESCH_SS_Y6;
 
-		for (i = 0; i < sch_ep->cs_count; i++)
-			if (test_bit(offset + i, tt->ss_bit_map))
-				return -ESCH_SS_OVERLAP;
-
 	} else {
 		u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
 
@@ -521,9 +515,6 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
 		if (cs_count > 7)
 			cs_count = 7; /* HW limit */
 
-		if (test_bit(offset, tt->ss_bit_map))
-			return -ESCH_SS_OVERLAP;
-
 		sch_ep->cs_count = cs_count;
 		/* one for ss, the other for idle */
 		sch_ep->num_budget_microframes = cs_count + 2;
@@ -544,11 +535,9 @@ 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 bw_updated;
-	int bits;
 	int i, j;
 
 	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
-	bits = (sch_ep->ep_type == ISOC_OUT_EP) ? sch_ep->cs_count : 1;
 
 	if (used)
 		bw_updated = sch_ep->bw_cost_per_microframe;
@@ -558,13 +547,6 @@ static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
 	for (i = 0; i < num_esit; i++) {
 		base = sch_ep->offset + i * sch_ep->esit;
 
-		for (j = 0; j < bits; j++) {
-			if (used)
-				set_bit(base + j, tt->ss_bit_map);
-			else
-				clear_bit(base + j, tt->ss_bit_map);
-		}
-
 		for (j = 0; j < sch_ep->cs_count; j++)
 			tt->fs_bus_bw[base + j] += bw_updated;
 	}

drivers/usb/host/xhci-mtk.h

@@ -24,12 +24,10 @@
 #define XHCI_MTK_MAX_ESIT	64
 
 /**
- * @ss_bit_map: used to avoid start split microframes overlay
  * @fs_bus_bw: array to keep track of bandwidth already used for FS
  * @ep_list: Endpoints using this TT
  */
 struct mu3h_sch_tt {
-	DECLARE_BITMAP(ss_bit_map, XHCI_MTK_MAX_ESIT);
 	u32 fs_bus_bw[XHCI_MTK_MAX_ESIT];
 	struct list_head ep_list;
 };