Jun Li wrote:
>
>> -----Original Message-----
>> From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
>> Sent: Thursday, July 23, 2020 4:36 AM
>> To: Jun Li <jun.li@xxxxxxx>; balbi@xxxxxxxxxx
>> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx
>> Subject: Re: [PATCH] usb: dwc3: debugfs: do not queue work if try to change mode
>> on non-drd
>>
>> Hi,
>>
>> Li Jun wrote:
>>> Do not try to queue a drd work for change mode if the port is not a
>>> drd, this is to avoid below kernel dump:
>> Are you talking about OTG or DRD? This patch seems to be for OTG. If you need to
>> debug and manually do role switch for DRD from userspace, enable and use role class
>> sysfs attribute.
> There is no problem in normal cases, I triggered this warning
> when try to change the role for a single role port via this debugfs
> file, I think nothing should stop user to use this file for debug
> purpose.
Ok.
>
> There is condition check of USB_DR_MODE_OTG when init drd_work, but
> no this check when queue work, so maybe a better change is to move
> the condition check from __dwc3_set_mode() into dwc3_set_mode()
Yeah, this looks better.
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 6adaa7d..2fa50ec 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -120,9 +120,6 @@ static void __dwc3_set_mode(struct work_struct *work)
> unsigned long flags;
> int ret;
>
> - if (dwc->dr_mode != USB_DR_MODE_OTG)
> - return;
> -
> pm_runtime_get_sync(dwc->dev);
>
> if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_OTG)
> @@ -205,6 +202,9 @@ void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
> {
> unsigned long flags;
>
> + if (dwc->dr_mode != USB_DR_MODE_OTG)
> + return;
> +
> spin_lock_irqsave(&dwc->lock, flags);
> dwc->desired_dr_role = mode;
> spin_unlock_irqrestore(&dwc->lock, flags);
>
BR,
Thinh
