diff options
| author | Bin Liu <b-liu@ti.com> | 2016-05-31 18:05:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-02 00:58:59 +0300 |
| commit | dbac5d07d13e330e6706813c9fde477140fb5d80 (patch) | |
| tree | 0a01a5d981d58b645c87ea29fcba781be628b823 /drivers/usb | |
| parent | b5801212229f6ca5c418c68cd1e0548f4b53f624 (diff) | |
| download | linux-dbac5d07d13e330e6706813c9fde477140fb5d80.tar.xz | |
usb: musb: host: don't start next rx urb if current one failed
urb->status is set when endpoint csr RXSTALL, H_ERROR, DATAERROR or
INCOMPRX bit is set. Those bits mean a broken pipe, so don't start next
urb when any of these bits is set by checking urb->status.
To minimize the risk of regression, only do so for RX, until we have a
test case to understand the behavior of TX.
The patch fixes system freeze issue caused by repeatedly invoking RX ISR
while removing a usb uart device connected to a hub, in which case the
hub has no chance to report the disconnect event due to the kernel is
busy in processing the RX interrupt flooding.
Fix checkpatch complaint (qh != NULL) as while.
Reported-by: Max Uvarov <muvarov@gmail.com>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/musb/musb_host.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 931381c51ad7..dd1ebde02786 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -434,7 +434,13 @@ static void musb_advance_schedule(struct musb *musb, struct urb *urb, } } - if (qh != NULL && qh->is_ready) { + /* + * The pipe must be broken if current urb->status is set, so don't + * start next urb. + * TODO: to minimize the risk of regression, only check urb->status + * for RX, until we have a test case to understand the behavior of TX. + */ + if ((!status || !is_in) && qh && qh->is_ready) { dev_dbg(musb->controller, "... next ep%d %cX urb %p\n", hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh)); musb_start_urb(musb, is_in, qh); |