Hi again,
Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes:
<snip>
> Try to dequeue a request that was already completed. Odd. Why are we
> missing a call to giveback??
Got a little more information:
file-storage-3982 [006] d... 131.010663: dwc3_ep_queue: ep1in: req 00000000eccaa10f length 0/16384 zsI ==> -115
file-storage-3982 [006] d... 131.010667: dwc3_prepare_trb: ep1in: trb 000000002ab8a1f9 buf 00000000bde24000 size 16384 ctrl 00000811 (Hlcs:sC:normal)
file-storage-3982 [006] d... 131.010674: dwc3_gadget_ep_cmd: ep1in: cmd 'Update Transfer' [30007] params 00000000 00000000 00000000 --> status: Successful
irq/16-dwc3-3983 [004] d... 131.010942: dwc3_event: event (00004086): ep1in: Transfer In Progress [0] (sIm)
irq/16-dwc3-3983 [004] d... 131.010942: dwc3_complete_trb: ep1in: trb 00000000426cd8cf buf 00000000bde20000 size 0 ctrl 00000810 (hlcs:sC:normal)
irq/16-dwc3-3983 [004] d... 131.010944: dwc3_gadget_giveback: ep1in: req 00000000f7765e56 length 16384/16384 zsI ==> 0
file-storage-3982 [006] d... 131.010994: dwc3_ep_queue: ep1in: req 00000000f7765e56 length 0/16384 zsI ==> -115
file-storage-3982 [006] d... 131.010998: dwc3_prepare_trb: ep1in: trb 0000000065d9143d buf 00000000bde28000 size 16384 ctrl 00000811 (Hlcs:sC:normal)
file-storage-3982 [006] d... 131.011005: dwc3_gadget_ep_cmd: ep1in: cmd 'Update Transfer' [30007] params 00000000 00000000 00000000 --> status: Successful
irq/16-dwc3-3983 [004] d... 131.065517: dwc3_event: event (00000001): Disconnect: [U0]
file-storage-3982 [006] .... 131.065558: dwc3_ep_dequeue: ep1in: req 00000000f7765e56 length 0/16384 zsI ==> -115
file-storage-3982 [006] d... 131.065687: dwc3_gadget_ep_cmd: ep1in: cmd 'End Transfer' [30d08] params 00000000 00000000 00000000 --> status: Successful
irq/16-dwc3-3983 [004] d... 131.065729: dwc3_event: event (080301c6): ep1in: Endpoint Command Complete
irq/16-dwc3-3983 [004] d... 131.065731: dwc3_gadget_giveback: ep1in: req 00000000f7765e56 length 0/16384 zsI ==> -104
file-storage-3982 [006] .... 131.065766: dwc3_ep_dequeue: ep1in: req 00000000eccaa10f length 0/16384 zsI ==> -115
irq/16-dwc3-3983 [004] d... 135.071714: dwc3_event: event (00000101): Reset [U0]
irq/16-dwc3-3983 [004] d... 135.126440: dwc3_event: event (00000201): Connection Done [U0]
From this snippet above it seems like we got End Transfer completed
*before* we tried to dequeue the request. This is a race in the driver,
since it will wait for End Transfer complete forever :-p We can see that
ep_dequeue won't send a new End Transfer unless it's necessary:
static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force)
{
struct dwc3 *dwc = dep->dwc;
struct dwc3_gadget_ep_cmd_params params;
u32 cmd;
int ret;
if ((dep->flags & DWC3_EP_END_TRANSFER_PENDING) ||
!dep->resource_index)
return;
[...]
}
So this will wait forever. Here's a patch that takes into consideration
this possibility:
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 17eb6619376a..cd9305d1cc0b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -384,19 +384,9 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
trace_dwc3_gadget_ep_cmd(dep, cmd, params, cmd_status);
- if (ret == 0) {
- switch (DWC3_DEPCMD_CMD(cmd)) {
- case DWC3_DEPCMD_STARTTRANSFER:
- dep->flags |= DWC3_EP_TRANSFER_STARTED;
- dwc3_gadget_ep_get_transfer_index(dep);
- break;
- case DWC3_DEPCMD_ENDTRANSFER:
- dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
- break;
- default:
- /* nothing */
- break;
- }
+ if (ret == 0 && DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
+ dep->flags |= DWC3_EP_TRANSFER_STARTED;
+ dwc3_gadget_ep_get_transfer_index(dep);
}
if (saved_config) {
@@ -1560,7 +1550,10 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
goto out0;
dwc3_gadget_move_cancelled_request(req);
- goto out0;
+ if (dep->flags & DWC3_EP_TRANSFER_STARTED)
+ goto out0;
+ else
+ break;
}
dev_err(dwc->dev, "request %pK was not queued to %s\n",
request, ep->name);
@@ -2578,7 +2571,8 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
cmd = DEPEVT_PARAMETER_CMD(event->parameters);
if (cmd == DWC3_DEPCMD_ENDTRANSFER) {
- dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
+ dep->flags &= ~(DWC3_EP_END_TRANSFER_PENDING |
+ DWC3_EP_TRANSFER_STARTED);
dwc3_gadget_ep_cleanup_cancelled_requests(dep);
}
break;
Note that this patch means we can get rid of END_TRANSFER_PENDING. We
should also update stop_active_transfer() to rely on TRANSFER_STARTED
instead of resource_index == 0.
--
balbi
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