Fail and WARN if DMA counters are wrong.

Signed-off-by: Aaro Koskinen <aaro.koski...@iki.fi>
---
 drivers/staging/octeon-usb/octeon-hcd.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/staging/octeon-usb/octeon-hcd.c 
b/drivers/staging/octeon-usb/octeon-hcd.c
index c761a39..54c23c4 100644
--- a/drivers/staging/octeon-usb/octeon-hcd.c
+++ b/drivers/staging/octeon-usb/octeon-hcd.c
@@ -2617,6 +2617,17 @@ static int cvmx_usb_poll_channel(struct cvmx_usb_state 
*usb, int channel)
                (pipe->transfer_dir == CVMX_USB_DIRECTION_OUT))
                pipe->flags |= CVMX_USB_PIPE_FLAGS_NEED_PING;
 
+       if (unlikely(WARN_ON_ONCE(bytes_this_transfer < 0))) {
+               /*
+                * In some rare cases the DMA engine seems to get stuck and
+                * keeps substracting same byte count over and over again. In
+                * such case we just need to fail every transaction.
+                */
+               cvmx_usb_perform_complete(usb, pipe, transaction,
+                                         CVMX_USB_COMPLETE_ERROR);
+               return 0;
+       }
+
        if (usbc_hcint.s.stall) {
                /*
                 * STALL as a response means this transaction cannot be
-- 
2.2.0

_______________________________________________
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Reply via email to