Re: [PATCH] USB: Fix xhci ERDP update issue

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Mar 18, 2022 at 08:17:50PM +0800, WeitaoWang-oc@zhaoxin.com wrote:
> On some situations, software handles TRB events slower than adding TRBs.
> If the number of TRB events to be processed in a given interrupt is 256.
> The local variable "event_ring_deq" that records in interrupt handler
> is equal to software_dequeue. It will cause driver not update ERDP,then
> software dequeue pointer is out of sync with ERDP on interrupt exit.
> On the next interrupt, the event ring may full but driver will not
> update ERDP as software_dequeue is equal to ERDP.
> 
> [  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
> 
> To avoid this issue by update software record local variable when
> handles 128 TRB events.
> 
> Fixes: dc0ffbea5729 ("usb: host: xhci: update event ring dequeue pointer on purpose")
> Signed-off-by: Weitao Wang <WeitaoWang-oc@zhaoxin.com>
> ---
>  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 d0b6806275e0..f9707997969d 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)
> -- 
> 2.17.1

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)
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  Please read the section entitled "The canonical patch format" in the
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If you wish to discuss this problem further, or you have questions about
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thanks,

greg k-h's patch email bot