usb: xhci-mtk: use first-fit for LS/FS

Use first-fit instead of best-fit for LS/FS devices under TT,
we found that best-fit will consume more bandwidth for some
cases.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20210507021127.54717-4-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 9fb7508..c07411d 100644 (file)
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -634,6 +634,11 @@ static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
                        min_bw = worst_bw;
                        min_index = offset;
                }
+
+               /* use first-fit for LS/FS */
+               if (sch_ep->sch_tt && min_index >= 0)
+                       break;
+
                if (min_bw == 0)
                        break;
        }