On Mon, Jul 22, 2024 at 03:07:38PM +0000, Łukasz Bartosik wrote: > DbC driver does not handle ClearFeature Halt requests correctly > which in turn may lead to dropping packets on the receive path. > > Below is a trace capture where due to incorrect handling of > ClearFeature Halt packet gets dropped on the receive path. > > /sys/kernel/debug/tracing # cat trace > 1) kworker/10:3-514 [010] d..1. 2925.601843: xhci_dbc_handle_event: > EVENT: TRB 000000019588c0e0 status 'Stall Error' len 0 slot 1 ep 2 > type 'Transfer Event' flags e:C > > 2) kworker/10:3-514 [010] d..1. 2925.613285: xhci_dbc_handle_event: > EVENT: TRB 000000019588bc80 status 'Stall Error' len 1024 slot 1 > ep 3 type 'Transfer Event' flags e:C > > 3) kworker/10:3-514 [010] d..1. 2925.619024: xhci_dbc_handle_transfer: > BULK: Buffer 0000000244b49800 length 1024 TD size 0 intr 0 type > 'Normal' flags b:i:I:c:s:i:e:C > > 4) kworker/10:3-514 [010] d..1. 2925.619025: xhci_dbc_giveback_request: > bulk-in: req 00000000a70b5ad2 length 0/1024 ==> -6 > > 5) kworker/10:3-514 [010] dNs2. 2925.623820: xhci_dbc_gadget_ep_queue: > BULK: Buffer 0000000244b49800 length 1024 TD size 0 intr 0 type > 'Normal' flags b:i:I:c:s:i:e:c > > 6) kworker/10:3-514 [010] dNs1. 2925.623823: xhci_dbc_queue_request: > bulk-in: req 00000000a70b5ad2 length 0/1024 ==> -115 > > 7) kworker/10:3-514 [010] d..1. 2925.629865: xhci_dbc_handle_event: > EVENT: TRB 000000019588bc80 status 'Short Packet' len 1000 slot 1 > ep 3 type 'Transfer Event' flags e:C > > 8) kworker/10:3-514 [010] d..1. 2925.635540: xhci_dbc_handle_event: > EVENT: TRB 000000019588bc90 status 'Short Packet' len 763 slot 1 > ep 3 type 'Transfer Event' flags e:C > > 9) kworker/10:3-514 [010] d..1. 2925.635540: xhci_dbc_handle_transfer: > BULK: Buffer 0000000244b49c00 length 1024 TD size 0 intr 0 type > 'Normal' flags b:i:I:c:s:i:e:C > > 10) kworker/10:3-514 [010] d..1. 2925.635541: xhci_dbc_giveback_request: > bulk-in: req 00000000b4ec77d7 length 261/1024 ==> 0 > > 11) kworker/10:3-514 [010] dNs2. 2925.635561: xhci_dbc_gadget_ep_queue: > BULK: Buffer 0000000244b49c00 length 1024 TD size 0 intr 0 type > 'Normal' flags b:i:I:c:s:i:e:c > > 12) kworker/10:3-514 [010] dNs1. 2925.635562: xhci_dbc_queue_request: > bulk-in: req 00000000b4ec77d7 length 0/1024 ==> -115 > > Lines 1 and 2 are Endpoints OUT and IN responses to receiving ClearFeature > Halt requests. > > Line 7 notifies of reception of 24 bytes packet. > > Line 8 notifies of reception of 261 bytes packet > > In Lines [9, 12] 261 bytes packet is being processed. > > However 24 bytes packet gets dropped. The kernel log includes entry which > is an indication of a packet drop: > [ 127.651845] xhci_hcd 0000:00:0d.0: no matched request > > This fix adds correct handling of ClearFeature Halt requests > by restarting an endpoint which received the request. > > Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver") > Signed-off-by: Łukasz Bartosik <ukaszb@xxxxxxxxxxxx> > --- > drivers/usb/host/xhci-dbgcap.c | 29 +++++++++++++++++++---------- > drivers/usb/host/xhci-dbgtty.c | 5 +++++ > 2 files changed, 24 insertions(+), 10 deletions(-) > > diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c > index 872d9cddbcef..b7af3a5ac98a 100644 > --- a/drivers/usb/host/xhci-dbgcap.c > +++ b/drivers/usb/host/xhci-dbgcap.c > @@ -173,7 +173,7 @@ static void xhci_dbc_giveback(struct dbc_request *req, int status) > spin_lock(&dbc->lock); > } > > -static void xhci_dbc_flush_single_request(struct dbc_request *req) > +static void xhci_dbc_flush_single_request(struct dbc_request *req, int status) So now we need to look up what "status" is here for every place this is called? That's going to be a pain, as you didn't even document it :( thanks, greg k-h