usb: xhci-mtk: fix the failure of bandwidth allocation

commit 5ce1a24dd98c00a57a8fa13660648abf7e08e3ef upstream.

The wMaxPacketSize field of endpoint descriptor may be zero
as default value in alternate interface, and they are not
actually selected when start stream, so skip them when try to
allocate bandwidth.

Cc: stable <stable@vger.kernel.org>
Fixes: 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller")
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1594360672-2076-1-git-send-email-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 d04fdd173ed2eff9bd77740cf69e1fc847b8ac7b..4bda7e7ee34274df4256435d6243c61fc933c755 100644 (file)
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -275,6 +275,10 @@ static bool need_bw_sch(struct usb_host_endpoint *ep,
        if (is_fs_or_ls(speed) && !has_tt)
                return false;
 
+       /* skip endpoint with zero maxpkt */
+       if (usb_endpoint_maxp(&ep->desc) == 0)
+               return false;
+
        return true;
 }