On 17-08-24 03:19 am, Thinh Nguyen wrote:
On Fri, Aug 16, 2024, Prashanth K wrote:
When operating in High-Speed, it is observed that DSTS[USBLNKST] doesn't update link state immediately after receiving the wakeup interrupt. Since wakeup event handler calls the resume callbacks, there is a chance that function drivers can perform an ep queue, which in turn tries to perform remote wakeup from send_gadget_ep_cmd(STARTXFER). This happens because DSTS[[21:18] wasn't updated to U0 yet, it's observed that the latency of DSTS can be in order of milli-seconds. Hence avoid calling gadget_wakeup during startxfer to prevent unnecessarily issuing remote wakeup to host.
Fixes: c36d8e947a56 ("usb: dwc3: gadget: put link to U0 before Start Transfer") Cc: stable@vger.kernel.org Suggested-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Signed-off-by: Prashanth K quic_prashk@quicinc.com
v2: Refactored the patch as suggested in v1 discussion.
drivers/usb/dwc3/gadget.c | 24 ------------------------ 1 file changed, 24 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 89fc690fdf34..3f634209c5b8 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -327,30 +327,6 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd, dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
Can you capture the notes I provided explaining why we can issue Start Transfer without checking for L1/L2/U3 states on top of this function?
I also thought the same initially, but didnt add since Greg usually adds the patch link to commit, so that the discussion would be captured in git log. I will add it on top of dwc3_send_gadget_ep_cmd and send V3, let me know if there's any other suggestion.
Thanks, Prashanth K