diff options
| author | Thinh Nguyen <Thinh.Nguyen@synopsys.com> | 2022-03-09 12:54:02 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-15 18:43:52 +0100 |
| commit | e4cf6580ac740f766dae26203bd6311d353dcd42 (patch) | |
| tree | 259c045c02c4feccc732b0aeeb5b8460001b6c3a /drivers/usb/dwc3/core.h | |
| parent | e192cc7b52399d1b073f88cd3ba128b74d3a57f1 (diff) | |
usb: dwc3: gadget: Wait for ep0 xfers to complete during dequeue
If a Setup packet is received but yet to DMA out, the controller will
not process the End Transfer command of any endpoint. Polling of its
DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a
command timeout.
This may occur if the driver doesn’t service the completion interrupt of
the control status stage yet due to system latency, then it won’t
prepare TRB and start the transfer for the next Setup Stage. To the host
side, the control transfer had completed, and the host can send a new
Setup packet at this point.
In the meanwhile, if the driver receives an async call to dequeue a
request (triggering End Transfer) to any endpoint, then the driver will
service that End transfer first, blocking the control status stage
completion handler. Since no TRB is available for the Setup stage, the
Setup packet can’t be DMA’ed out and the End Transfer gets hung.
The driver must not block setting up of the Setup stage. So track and
only issue the End Transfer command only when there’s Setup TRB prepared
so that the controller can DMA out the Setup packet. Delay the End
transfer command if there's no Setup TRB available. This is applicable to
all DWC_usb3x IPs.
Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20220309205402.4467-1-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/core.h')
| -rw-r--r-- | drivers/usb/dwc3/core.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index ea3ca04406bb..e9b1e9b8f1f3 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -737,6 +737,7 @@ struct dwc3_ep { #define DWC3_EP_FIRST_STREAM_PRIMED BIT(10) #define DWC3_EP_PENDING_CLEAR_STALL BIT(11) #define DWC3_EP_TXFIFO_RESIZED BIT(12) +#define DWC3_EP_DELAY_STOP BIT(13) /* This last one is specific to EP0 */ #define DWC3_EP0_DIR_IN BIT(31) |