Re: [PATCH v2 2/2] usb: dwc3: gadget: Improve dwc3_gadget_suspend() and dwc3_gadget_resume()

On Tue, May 02, 2023, Roger Quadros wrote:

Prevent -ETIMEDOUT error on .suspend(). e.g. If gadget driver is loaded and we are connected to a USB host, all transfers must be stopped before stopping the controller else we will not get a clean stop i.e. dwc3_gadget_run_stop() will take several seconds to complete and will return -ETIMEDOUT.

Handle error cases properly in dwc3_gadget_suspend(). Simplify dwc3_gadget_resume() by using the introduced helper function.

Fixes: 9f8a67b65a49 ("usb: dwc3: gadget: fix gadget suspend/resume") Cc: stable@vger.kernel.org Suggested-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Signed-off-by: Roger Quadros rogerq@kernel.org

---

drivers/usb/dwc3/gadget.c | 66 +++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 33 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index b5170374cd18..869f1695565d 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2699,6 +2699,21 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc) return ret; } +static int dwc3_gadget_soft_connect(struct dwc3 *dwc) +{

• /*

• * In the Synopsys DWC_usb31 1.90a programming guide section
  

• * 4.1.9, it specifies that for a reconnect after a
  

• * device-initiated disconnect requires a core soft reset
  

• * (DCTL.CSftRst) before enabling the run/stop bit.
  

• */
  

• dwc3_core_soft_reset(dwc);
• dwc3_event_buffers_setup(dwc);
• __dwc3_gadget_start(dwc);
• return dwc3_gadget_run_stop(dwc, true);

+}

static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) { struct dwc3 *dwc = gadget_to_dwc(g); @@ -2737,21 +2752,10 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) synchronize_irq(dwc->irq_gadget);

• if (!is_on) {

• if (!is_on) ret = dwc3_gadget_soft_disconnect(dwc);

• } else {

• /*
  

•  * In the Synopsys DWC_usb31 1.90a programming guide section
  

•  * 4.1.9, it specifies that for a reconnect after a
  

•  * device-initiated disconnect requires a core soft reset
  

•  * (DCTL.CSftRst) before enabling the run/stop bit.
  

•  */
  

• dwc3_core_soft_reset(dwc);
  

• dwc3_event_buffers_setup(dwc);
  

• __dwc3_gadget_start(dwc);
  

• ret = dwc3_gadget_run_stop(dwc, true);
  

• }

• else

• ret = dwc3_gadget_soft_connect(dwc);
  

pm_runtime_put(dwc->dev); @@ -4655,42 +4659,38 @@ void dwc3_gadget_exit(struct dwc3 *dwc) int dwc3_gadget_suspend(struct dwc3 *dwc) { unsigned long flags;

• int ret;

if (!dwc->gadget_driver || !dwc->softconnect) return 0;

• dwc3_gadget_run_stop(dwc, false);

• ret = dwc3_gadget_soft_disconnect(dwc);
• if (ret)

• goto err;
  

spin_lock_irqsave(&dwc->lock, flags); dwc3_disconnect_gadget(dwc);

• __dwc3_gadget_stop(dwc); spin_unlock_irqrestore(&dwc->lock, flags);

return 0;

+err:

• /*

• * Attempt to reset the controller's state. Likely no
  

• * communication can be established until the host
  

• * performs a port reset.
  

• */
  

• dwc3_gadget_soft_connect(dwc);
• return ret;

} int dwc3_gadget_resume(struct dwc3 *dwc) {

• int ret;
• if (!dwc->gadget_driver || !dwc->softconnect) return 0;

• ret = __dwc3_gadget_start(dwc);
• if (ret < 0)

• goto err0;
  

• ret = dwc3_gadget_run_stop(dwc, true);
• if (ret < 0)

• goto err1;
  

• return 0;

-err1:

• __dwc3_gadget_stop(dwc);

-err0:

• return ret;

• return dwc3_gadget_soft_connect(dwc);

} void dwc3_gadget_process_pending_events(struct dwc3 *dwc) -- 2.34.1

Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com

Thanks, Thinh