Revert "usb: musb: musb_host: Enable HCD_BH flag to handle urb return in bottom half"
authorBin Liu <b-liu@ti.com>
Mon, 25 Apr 2016 20:53:30 +0000 (15:53 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 26 Apr 2016 21:50:02 +0000 (14:50 -0700)
This reverts commit 2035772010db634ec8566b658fb1cd87ec47ac77.

Commit 20357720 claims throughput improvement for MSC/UVC, but I
don't see much improvement. Following are the MSC measurement using
dd on AM335x GP EVM.

with BCD_BH:    read: 14.9MB/s, write: 20.9MB/s
without BCD_BH: read: 15.2MB/s, write: 21.2MB/s

However with this commit the following regressions have been observed.

1. ASIX usb-ethernet dongle is completely broken on UDP RX.

2. Unpluging a 3G modem, which uses option driver, behind a hub causes
   console log flooding with the following message.

   option_instat_callback: error -71

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/musb/musb_host.c

index 58487a4..2f8ad7f 100644 (file)
@@ -2735,7 +2735,7 @@ static const struct hc_driver musb_hc_driver = {
        .description            = "musb-hcd",
        .product_desc           = "MUSB HDRC host driver",
        .hcd_priv_size          = sizeof(struct musb *),
-       .flags                  = HCD_USB2 | HCD_MEMORY | HCD_BH,
+       .flags                  = HCD_USB2 | HCD_MEMORY,
 
        /* not using irq handler or reset hooks from usbcore, since
         * those must be shared with peripheral code for OTG configs