Re: [PATCH] USB: Fix xhci ERDP update issue
From: WeitaoWang-oc@xxxxxxxxxxx
Date: Wed Mar 16 2022 - 08:47:26 EST
On 2022/3/16 19:57, Peter Chen wrote:
On Mon, Mar 14, 2022 at 10:34 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
On Mon, Mar 14, 2022 at 03:25:23PM +0800, WeitaoWang-oc@xxxxxxxxxxx wrote:
On some situations, software handles TRB events slower than adding TRBs,
xhci_irq will not exit until all events are handled. If xhci_irq just
handles 256 TRBs and exit, the temp variable(event_ring_deq) driver records
in xhci irq is equal to driver current dequeue pointer. It will cause driver
not update ERDP and software dequeue pointer lost sync with ERDP. On the
next xhci_irq, the event ring is full but driver will not update ERDP as
software dequeue pointer is equal to ERDP.
At the current driver, the ERDP is updated at most 128 TRBs, how is
the above condition
triggered?
Peter
If the number of TRB events to be processed in a given interrupt is 256.
ERDP is updated after only the first 128 TRB evnets are processed.
It will not be updated when another 128 TRB evnets are processed as
event_ring_deq= "xhci->event_ring->dequeue", which will cause the
software-recorded dequeue pointer is out of sync with ERDP on interrupt
exit.
Weitao Wang
[ 536.377115] xhci_hcd 0000:00:12.0: ERROR unknown event type 37
[ 566.933173] sd 8:0:0:0: [sdb] tag#27 uas_eh_abort_handler 0 uas-tag 7
inflight: CMD OUT
[ 566.933181] sd 8:0:0:0: [sdb] tag#27 CDB: Write(10) 2a 00 17 71 e6 78 00
00 08 00
[ 572.041186] xhci_hcd On some situataions,the0000:00:12.0: xHCI host not
responding to stop endpoint command.
[ 572.057193] xhci_hcd 0000:00:12.0: Host halt failed, -110
[ 572.057196] xhci_hcd 0000:00:12.0: xHCI host controller not responding,
assume dead
[ 572.057236] sd 8:0:0:0: [sdb] tag#26 uas_eh_abort_handler 0 uas-tag 6
inflight: CMD
[ 572.057240] sd 8:0:0:0: [sdb] tag#26 CDB: Write(10) 2a 00 38 eb cc d8 00
00 08 00
[ 572.057244] sd 8:0:0:0: [sdb] tag#25 uas_eh_abort_handler 0 uas-tag 5
inflight: CMD
Fixed this issue by update software record temp variable when handles 128
TRB events.
Signed-off-by: Weitao Wang <WeitaoWang-oc@xxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d0b6806..f970799 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3141,6 +3141,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
if (event_loop++ < TRBS_PER_SEGMENT / 2)
continue;
xhci_update_erst_dequeue(xhci, event_ring_deq);
+ event_ring_deq = xhci->event_ring->dequeue;
/* ring is half-full, force isoc trbs to interrupt more
often */
if (xhci->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN)
--
2.7.4
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him
a patch that has triggered this response. He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created. Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.
You are receiving this message because of the following common error(s)
as indicated below:
- Your patch is malformed (tabs converted to spaces, linewrapped, etc.)
and can not be applied. Please read the file,
Documentation/email-clients.txt in order to fix this.
If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.
thanks,
greg k-h's patch email bot
.