On Tue, Feb 28, 2023 at 12:24:18PM -0800, Wesley Cheng wrote:
> Previously, there was a 100uS delay inserted after issuing an end transfer
> command for specific controller revisions. This was due to the fact that
> there was a GUCTL2 bit field which enabled synchronous completion of the
> end transfer command once the CMDACT bit was cleared in the DEPCMD
> register. Since this bit does not exist for all controller revisions, add
> the delay back in, and increase the duration to 1ms for the controller to
> complete the command.
>
> An issue was seen where the USB request buffer was unmapped while the DWC3
> controller was still accessing the TRB. However, it was confirmed that the
> end transfer command was successfully submitted. (no end transfer timeout)
> In situations, such as dwc3_gadget_soft_disconnect() and
> __dwc3_gadget_ep_disable(), the dwc3_remove_request() is utilized, which
> will issue the end transfer command, and follow up with
> dwc3_gadget_giveback(). At least for the USB ep disable path, it is
> required for any pending and started requests to be completed and returned
> to the function driver in the same context of the disable call. Without
> the GUCTL2 bit, it is not ensured that the end transfer is completed before
> the buffers are unmapped.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> ---
> Changes in v3:
> - Fixed subject title and modified commit text to reference the new 1ms
> delay
>
> Changes in v2:
> - Increase delay value to 1ms
> - Make this applicable to DWC32 revisions as well
>
> drivers/usb/dwc3/gadget.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 3c63fa97a680..15adf07a4df4 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1699,6 +1699,7 @@ static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
> */
> static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool interrupt)
> {
> + struct dwc3 *dwc = dep->dwc;
> struct dwc3_gadget_ep_cmd_params params;
> u32 cmd;
> int ret;
> @@ -1722,10 +1723,14 @@ static int __dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force, bool int
> WARN_ON_ONCE(ret);
> dep->resource_index = 0;
>
> - if (!interrupt)
> + if (!interrupt) {
> + if (DWC3_IP_IS(DWC32) || DWC3_IP_IS(DWC31) ||
> + DWC3_VER_IS_PRIOR(DWC3, 310A))
How about a little more succinctly:
if (!DWC3_IP_IS(DWC3) || DWC3_VER_IS_PRIOR(DWC3, 310A))
?
Jack
