On 2022/3/15 下午4:08, Mathias Nyman wrote:
On 14.3.2022 9.25, 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.
[ 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>
Thanks
Solution itself looks good but patch has some minor format issue:
It would also be interesting to know if the full event ring was triggered in a real
life usecase?
If that is the case I might need to look more into it.
Bigger event ring, more rings, faster handler, avoid irqoff time...
Thanks
Mathias
.
Some performance test tools such as fio or iometer can be used to reproduce
this case, If tested with 4KB read or write. xHCI will generate a lost TRB
events fast than software consume on a certain period of time. Once
the interrupt is entered, software may handle more than 128 TRBs at a time.
While the software is processing, xHCI is still generating events. This may
has problems caused by the ERDP update mechanism. If update software
record temp variable when handles 128 TRB events, event ring full will not
happen any more even though fio test with 4KB read or write.
Thanks
Weitao Wang
