On 28/04/2023 01:13, Thinh Nguyen wrote:
> On Thu, Apr 27, 2023, Roger Quadros wrote:
>> Hi,
>>
>> On 26/04/2023 23:01, Thinh Nguyen wrote:
>>> Hi,
>>>
>>> On Wed, Apr 26, 2023, Roger Quadros wrote:
>>>> Hi Thinh,
>>>>
>>>> On Linux kernel v6.3
>>>> Test procedure:
>>>>
>>>> - modprobe g_zero
>>>> - Connect to PC host
>>>> - systemctl suspend
>>>>
>>>> A large delay of 3 seconds is observed. The delay comes from dwc3_gadget_suspend()->dwc3_gadget_run_stop() waiting for DWC3_DSTS_DEVCTRLHLT to be set.
>>>> It returns -ETIMEDOUT.
>>>>
>>>> Are we missing something to do a clean stop during suspend?
>>>>
>>>> FYI. Unloading g_zero does not show this delay on stop.
>>>>
>>>> cheers,
>>>> -roger
>>>
>>> When clearing run_stop bit and the controller doesn't halt, that usually
>>> means there are active transfers/endpoints that aren't ended yet.
>>>
>>> The dwc3_gadget_suspend() doesn't properly do all the cleanup before
>>> clearing the run_stop bit. I think you just need to call
>>> dwc3_gadget_soft_disconnect() in dwc3_gadget_suspend() to fix this.
>>
>> That seems to do the trick.
>> How does this look?
>>
>> -------------------------- drivers/usb/dwc3/gadget.c --------------------------
>> @@ -4674,11 +4676,18 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
>> int dwc3_gadget_suspend(struct dwc3 *dwc)
>> {
>> unsigned long flags;
>> + int ret;
>>
>> - if (!dwc->gadget_driver)
>> + if (!dwc->gadget_driver || !dwc->softconnect)
>> return 0;
>>
>> - dwc3_gadget_run_stop(dwc, false, false);
>> + ret = dwc3_gadget_soft_disconnect(dwc);
>> + if (ret)
>> + goto err0;
>> +
>> + ret = dwc3_gadget_run_stop(dwc, false, false);
>> + if (ret)
>> + goto err1;
>>
>
> We already clear run_stop in dwc3_gadget_soft_disconnect().
>
> Can you try the following change (not tested):
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index c0ca4d12f95d..2996bcb4d53d 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);
return dwc3_gadget_run_stop(dwc, true, false);
> +}> +
> 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 +4659,39 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
> int dwc3_gadget_suspend(struct dwc3 *dwc)
> {
> unsigned long flags;
> + int ret;
>
> if (!dwc->gadget_driver)
We need to check for dwc->softconnect here. If it is not set that means
controller has already stopped so we can simply exit.
> 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.
> + */
> + if (dwc->softconnect)
> + 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)
Everything else looks ok. I will send a patch soon.
--
cheers,
-roger
