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 defaf950e63142ea2d1eb6627ac696ebd5ca5786..7120dbfaacaba38513662d178b69bf641ce125e8 100644 (file)
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -284,6 +284,10 @@ 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;
 }