Re: [PATCH 1/1] usb: dwc2: gadget: don't try to disable ep0 in dwc2_hsotg_suspend

[Amelie DELAUNAY]

Hi Minas,

On 12/14/21 7:22 AM, Minas Harutyunyan wrote:
> Hi Amelie,
>
> On 12/7/2021 5:01 PM, Amelie Delaunay wrote:
> > Calling dwc2_hsotg_ep_disable on ep0 (in/out) will lead to the following
> > logs before returning -EINVAL:
> > dwc2 49000000.usb-otg: dwc2_hsotg_ep_disable: called for ep0
> > dwc2 49000000.usb-otg: dwc2_hsotg_ep_disable: called for ep0
>
> This messages printed for EP0 OUT which can't be disabled, but EP0 IN
> can and should be disabled. Your patch exclude EP0 IN from disabling flow.


Thanks for the review. I wonder why then in dwc2_hsotg_udc_stop and 
dwc2_hsotg_core_init_disconnected EP0 IN is not disabled (loop starts 
from EP1) ?

Due to:
	/* Same dwc2_hsotg_ep is used in both directions for ep0 */
	hsotg->eps_out[0] = hsotg->eps_in[0];

the condition in dwc2_hsotg_ep_disable to display the error is always 
true for EP0, whatever the direction, so the log appears for EP0 IN & OUT:
	if (ep == &hsotg->eps_out[0]->ep) {
		dev_err(hsotg->dev, "%s: called for ep0\n", __func__);
		return -EINVAL;
	}

Should all loops need to be fixed to start loop from EP0 but exclude EP0 
OUT from being disabled, so that EP0 IN can be disabled ? e.g. for 
dwc2_hsotg_suspend:
	

$ git diff drivers/usb/dwc2/gadget.c
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 11d85a6e0b0d..0c12219bfbf4 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -4231,7 +4231,7 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep)

        dev_dbg(hsotg->dev, "%s(ep %p)\n", __func__, ep);

-       if (ep == &hsotg->eps_out[0]->ep) {
+       if (ep == &hsotg->eps_out[0]->ep && !dir_in) {
                dev_err(hsotg->dev, "%s: called for ep0\n", __func__);
                return -EINVAL;
        }
@@ -5077,7 +5077,7 @@ int dwc2_hsotg_suspend(struct dwc2_hsotg *hsotg)
                for (ep = 0; ep < hsotg->num_of_eps; ep++) {
                        if (hsotg->eps_in[ep])

dwc2_hsotg_ep_disable_lock(&hsotg->eps_in[ep]->ep);
-                       if (hsotg->eps_out[ep])
+                       if (ep > 0 && hsotg->eps_out[ep])

dwc2_hsotg_ep_disable_lock(&hsotg->eps_out[ep]->ep);
                }
        }

Regards,
Amelie

> Thanks,
> Minas
>
> > To avoid these two logs while suspending, start disabling the endpoint
> > from the index 1, as done in dwc2_hsotg_udc_stop:
> >
> > 	/* all endpoints should be shutdown */
> > 	for (ep = 1; ep < hsotg->num_of_eps; ep++) {
> > 		if (hsotg->eps_in[ep])
> > 			dwc2_hsotg_ep_disable_lock(&hsotg->eps_in[ep]->ep);
> > 		if (hsotg->eps_out[ep])
> > 			dwc2_hsotg_ep_disable_lock(&hsotg->eps_out[ep]->ep);
> > 	}
> >
> > Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
> > ---
> >    drivers/usb/dwc2/gadget.c | 2 +-
> >    1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> > index b884a83b26a6..ee31f9a328da 100644
> > --- a/drivers/usb/dwc2/gadget.c
> > +++ b/drivers/usb/dwc2/gadget.c
> > @@ -5086,7 +5086,7 @@ int dwc2_hsotg_suspend(struct dwc2_hsotg *hsotg)
> >    		hsotg->gadget.speed = USB_SPEED_UNKNOWN;
> >    		spin_unlock_irqrestore(&hsotg->lock, flags);
> >    
> > -		for (ep = 0; ep < hsotg->num_of_eps; ep++) {
> > +		for (ep = 1; ep < hsotg->num_of_eps; ep++) {
> >    			if (hsotg->eps_in[ep])
> >    				dwc2_hsotg_ep_disable_lock(&hsotg->eps_in[ep]->ep);
> >    			if (hsotg->eps_out[ep])