Re: usb: musb: regression since 4.9 on omap4-panda-es (caused by d8e5f0eca1e8)

[Bin Liu <b-liu-l0cyMroinI0@public.gmane.org>]

On Wed, Apr 05, 2017 at 08:29:55AM -0700, Tony Lindgren wrote:
> * Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [170405 06:53]:
> > * Peter Ujfalusi <peter.ujfalusi-l0cyMroinI0@public.gmane.org> [170405 00:15]:
> > > To be precise this is what I have tried:
> > > - boot w/o cable connected
> > > - boot w/ board connected to PC (device mode)
> > > - boot w/ OTG-A cable with USB keyboard
> > > - boot w/ OTG-A cable connected to powered USB hub and the same keyboard
> > > 
> > > w/ and w/o this patch I have the same flood of prints in all cases.
> > 
> > OK interesting that it also happens with nothing connected.
> > 
> > > Fwiw I have checked where the is_active is set - which causes the prints:
> > > musb_core.c:musb_start()
> > > 
> > > if (musb->port_mode != MUSB_PORT_MODE_HOST &&
> > > 		musb->xceiv->otg->state != OTG_STATE_A_WAIT_BCON &&
> > > 		(devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS) {
> > > 	musb->is_active = 1;
> > > } else {
> > > 	devctl |= MUSB_DEVCTL_SESSION;
> > > }
> > > 
> > > this was the only place where the is_active was set to 1.
> > 
> > That seems normal in musb_start(). Will try with your .config
> > here.
> 
> If the the port is configured as OTG, we should not need to
> try to force any states during init. The change below will stop

True, but the code has been there for a very long time, any idea what
causes the regression?

Regards,
-Bin.

> the warnings with your .config, needs to be tested more though
> to make sure things still work in all cases.
> 
> Regards,
> 
> Tony
> 
> 8< --------------------------
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -2780,10 +2780,11 @@ int musb_host_setup(struct musb *musb, int power_budget)
>  	int ret;
>  	struct usb_hcd *hcd = musb->hcd;
>  
> -	MUSB_HST_MODE(musb);
> -	musb->xceiv->otg->default_a = 1;
> -	musb->xceiv->otg->state = OTG_STATE_A_IDLE;
> -
> +	if (musb->port_mode == MUSB_PORT_MODE_HOST) {
> +		MUSB_HST_MODE(musb);
> +		musb->xceiv->otg->default_a = 1;
> +		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
> +	}
>  	otg_set_host(musb->xceiv->otg, &hcd->self);
>  	hcd->self.otg_port = 1;
>  	musb->xceiv->otg->host = &hcd->self;
> -- 
> 2.12.2
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