[PATCH 4.9 20/39] Revert "usb: musb: host: dont start next rx urb if current one failed"

From: Greg Kroah-Hartman
Date: Mon Feb 26 2018 - 15:21:52 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bin Liu <b-liu@xxxxxx>

commit 44eb5e12b845cc8a0634f21b70ef07d774eb4b25 upstream.

This reverts commit dbac5d07d13e330e6706813c9fde477140fb5d80.

commit dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed")
along with commit b5801212229f ("usb: musb: host: clear rxcsr error bit if set")
try to solve the issue described in [1], but the latter alone is
sufficient, and the former causes the issue as in [2], so now revert it.

[1] https://marc.info/?l=linux-usb&m=146173995117456&w=2
[2] https://marc.info/?l=linux-usb&m=151689238420622&w=2

Cc: stable@xxxxxxxxxxxxxxx # v4.7+
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/musb/musb_host.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -418,13 +418,7 @@ static void musb_advance_schedule(struct
}
}

- /*
- * 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) {
+ if (qh != NULL && qh->is_ready) {
musb_dbg(musb, "... next ep%d %cX urb %p",
hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
musb_start_urb(musb, is_in, qh);