Messages in this thread | | | Date | Wed, 16 Mar 2022 20:47:14 +0800 | Subject | Re: [PATCH] USB: Fix xhci ERDP update issue | From | "" <> |
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On 2022/3/16 19:57, Peter Chen wrote: > On Mon, Mar 14, 2022 at 10:34 PM Greg KH <gregkh@linuxfoundation.org> wrote: >> >> On Mon, Mar 14, 2022 at 03:25:23PM +0800, WeitaoWang-oc@zhaoxin.com 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@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 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 > .
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