Re: [PATCH v2 3/3] usb: dwc3: imx8mp: disable auto suspend for host role

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Thu, Jan 08, 2026, Xu Yang wrote:
> On Tue, Dec 16, 2025 at 11:26:40PM +0000, Thinh Nguyen wrote:
> > On Fri, Dec 05, 2025, Xu Yang wrote:
> > > Do dwc3 core auto suspend enable for device and disable for host
> > > , this can make sure dwc3 core device auto suspend setting is
> > > correct all the time, the background of disable dwc3 core device
> > > auto suspend is to make its parent device suspend immediately
> > > (so wakeup enable can be enabled) after xhci-plat device suspended,
> > > for device mode, we keep the dwc3 core device auto suspend is to
> > > give some wait for gadget to be enumerated.
> > > 
> > > Note: It's a temporary solution until we switch to using the new
> > >       flatten model.
> > > 
> > > Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> > > 
> > > ---
> > > Changes in v2:
> > >  - add a note suggested by Thinh
> > > ---
> > >  drivers/usb/dwc3/dwc3-imx8mp.c | 31 +++++++++++++++++++++++++++++++
> > >  1 file changed, 31 insertions(+)
> > > 
> > > diff --git a/drivers/usb/dwc3/dwc3-imx8mp.c b/drivers/usb/dwc3/dwc3-imx8mp.c
> > > index 8bece4baecbf..2e13ca588f42 100644
> > > --- a/drivers/usb/dwc3/dwc3-imx8mp.c
> > > +++ b/drivers/usb/dwc3/dwc3-imx8mp.c
> > > @@ -158,11 +158,31 @@ static irqreturn_t dwc3_imx8mp_interrupt(int irq, void *_dwc3_imx)
> > >  	return IRQ_HANDLED;
> > >  }
> > >  
> > > +static void dwc3_imx_pre_set_role(struct dwc3 *dwc, enum usb_role role)
> > > +{
> > > +	if (role == USB_ROLE_HOST)
> > > +		/*
> > > +		 * For xhci host, we need disable dwc core auto
> > > +		 * suspend, because during this auto suspend delay(5s),
> > > +		 * xhci host RUN_STOP is cleared and wakeup is not
> > > +		 * enabled, if device is inserted, xhci host can't
> > > +		 * response the connection.
> > > +		 */
> > > +		pm_runtime_dont_use_autosuspend(dwc->dev);
> > 
> > As noted previously, don't we need to unwind this in dwc3_imx8mp_remove
> > if the current mode device?
> 
> Thanks for the reminder. I check it, dwc3_core_remove() will call
> pm_runtime_dont_use_autosuspend(). So it seems unnecessary to unwind it
> again in dwc3_imx8mp_remove().
> 

Thanks for checking.

BR,
Thinh