Re: [PATCH] usb: chipidea: fix ci_irq for role-switching use-case

[Philippe Schenker <philippe.schenker@toradex.com>]

On Tue, 2020-06-30 at 00:43 +0000, Peter Chen wrote:
> On 20-06-29 10:04:13, Philippe Schenker wrote:
> > On Mon, 2020-06-29 at 07:26 +0000, Peter Chen wrote:
> > > On 20-06-26 13:03:11, Philippe Schenker wrote:
> > > > If the hardware is in low-power-mode and one plugs in device or
> > > > host
> > > > it did not switch the mode due to the early exit out of the
> > > > interrupt.
> > > 
> > > Do you mean there is no coming call for role-switch? Could you
> > > please
> > > share
> > > your dts changes? Try below patch:
> > 
> > Here are my DTS changes:
> > 
> > diff --git a/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
> > b/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
> > index 97601375f2640..c424f707a1afa 100644
> > --- a/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
> > +++ b/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
> > @@ -13,6 +13,13 @@
> >                 stdout-path = "serial0:115200n8";
> >         };
> >  
> > +       extcon_usbc_det: usbc_det {
> > +               compatible = "linux,extcon-usb-gpio";
> > +               id-gpio = <&gpio7 14 GPIO_ACTIVE_HIGH>;
> > +               pinctrl-names = "default";
> > +               pinctrl-0 = <&pinctrl_usbc_det>;
> > +       };
> > +
> >         /* fixed crystal dedicated to mpc258x */
> >         clk16m: clk16m {
> >                 compatible = "fixed-clock";
> > @@ -174,6 +181,7 @@
> >  };
> >  
> >  &usbotg1 {
> > +       extcon = <&extcon_usbc_det>, <&extcon_usbc_det>;
> 
> If you have only ID extcon, but no VBUS extcon, you only need to
> add only phandle, see dt-binding for detail please.

You where right again! Thanks, this actually solves the RNDIS issue for
our colibri-imx7 board:

+       extcon = <0>, <&extcon_usbc_det>;

Howevever on this iMX7 board we have VBUS hooked up to the SoC, that's
why it works only with ID.

On Colibri-iMX6ULL we do not have VBUS hooked up. So device/host
switching works only with 'extcon = <&extcon_usbc_det>,
<&extcon_usbc_det>;' but then RNDIS and also a normal thumb-drive does
not work. How could I work around this fact? A dummy-gpio that would
always read "high" for vbus would be a solution for me.

Philippe

> 
> >         status = "okay";
> >  };
> >  
> > diff --git a/arch/arm/boot/dts/imx7-colibri.dtsi
> > b/arch/arm/boot/dts/imx7-colibri.dtsi
> > index e18e89dec8792..caea90d2421fd 100644
> > --- a/arch/arm/boot/dts/imx7-colibri.dtsi
> > +++ b/arch/arm/boot/dts/imx7-colibri.dtsi
> > @@ -457,7 +457,7 @@
> >  };
> >  
> >  &usbotg1 {
> > -       dr_mode = "host";
> > +       dr_mode = "otg";
> >  };
> >  
> >  &usdhc1 {
> > @@ -486,7 +486,7 @@
> >  &iomuxc {
> >         pinctrl-names = "default";
> >         pinctrl-0 = <&pinctrl_gpio1 &pinctrl_gpio2 &pinctrl_gpio3
> > &pinctrl_gpio4
> > -                    &pinctrl_gpio7 &pinctrl_usbc_det>;
> > +                    &pinctrl_gpio7>;
> >  
> >         pinctrl_gpio1: gpio1-grp {
> >                 fsl,pins = <
> > 
> > > 
> > > diff --git a/drivers/usb/chipidea/core.c
> > > b/drivers/usb/chipidea/core.c
> > > index e8ce300ad490..9e10dcfeb98f 100644
> > > --- a/drivers/usb/chipidea/core.c
> > > +++ b/drivers/usb/chipidea/core.c
> > > @@ -1313,6 +1313,29 @@ static void ci_controller_suspend(struct
> > > ci_hdrc *ci)
> > >  	enable_irq(ci->irq);
> > >  }
> > >  
> > > +/*
> > > + * Handle the wakeup interrupt triggered by extcon connector
> > > + * We need to call ci_irq again for extcon since the first
> > > + * interrupt (wakeup int) only let the controller be out of
> > > + * low power mode, but not handle any interrupts.
> > > + */
> > > +static void ci_extcon_wakeup_int(struct ci_hdrc *ci)
> > > +{
> > > +	struct ci_hdrc_cable *cable_id, *cable_vbus;
> > > +	u32 otgsc = hw_read_otgsc(ci, ~0);
> > > +
> > > +	cable_id = &ci->platdata->id_extcon;
> > > +	cable_vbus = &ci->platdata->vbus_extcon;
> > > +
> > > +	if (!IS_ERR(cable_id->edev) && ci->is_otg &&
> > > +		(otgsc & OTGSC_IDIE) && (otgsc & OTGSC_IDIS))
> > > +		ci_irq(ci->irq, ci);
> > > +
> > > +	if (!IS_ERR(cable_vbus->edev) && ci->is_otg &&
> > > +		(otgsc & OTGSC_BSVIE) && (otgsc & OTGSC_BSVIS))
> > > +		ci_irq(ci->irq, ci);
> > > +}
> > > +
> > >  static int ci_controller_resume(struct device *dev)
> > >  {
> > >  	struct ci_hdrc *ci = dev_get_drvdata(dev);
> > > @@ -1343,6 +1366,7 @@ static int ci_controller_resume(struct
> > > device
> > > *dev)
> > >  		enable_irq(ci->irq);
> > >  		if (ci_otg_is_fsm_mode(ci))
> > >  			ci_otg_fsm_wakeup_by_srp(ci);
> > > +		ci_extcon_wakeup_int(ci);
> > >  	}
> > >  
> > >  	return 0;
> > 
> > Thanks for creating this patch! I wanted also something like that,
> > but
> > couldn't find out where to put it. 
> > 
> > I tried this patch and with the above devicetree changes this works
> > perfectly! Thanks Peter!
> > 
> > Should I send the patch with you as the "Suggested-by" or do you
> > want to
> > send the patch so you are the Author? I would have it ready in my
> > git
> > repo.
> 
> This patch was a part of one patch at downstream, I will submit one
> and
> add your tags.

Perfect, thank you!
> 
> > > > Hi Peter
> > > > 
> > > > During my investigation I found a bug in ci_irq. I would
> > > > appreciate
> > > > if you could review this. From what I see this patch should be
> > > > save
> > > > to apply.
> > > > 
> > > > This patch does not solve all of our issues. When I have
> > > > RUNTIME_PM
> > > > enabled on imx6ull or imx7. RNDIS still does not come up. So
> > > > there
> > > > has to be another bug hiding somewhere in the Runtime PM code to
> > > > prevent
> > > > RNDIS from working properly. I quickly looked through your
> > > > patches
> > > > that added this stuff back in 2015 but couldn't spot anything
> > > > related to
> > > > usb gadget-mode.
> > > > 
> > > > If you right away know where the problem could be hiding itself,
> > > > I would appreciate a hint.
> > > > 
> > > 
> > > I need information for call trace for further suggestion.
> 
> With this patch, does your RNDIS issue be fixed or still not?
> 
> Peter
> > > Peter
> > > 
> > > > ---
> > > > 
> > > >  drivers/usb/chipidea/core.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/usb/chipidea/core.c
> > > > b/drivers/usb/chipidea/core.c
> > > > index 9a7c53d09ab4..5159420a23a4 100644
> > > > --- a/drivers/usb/chipidea/core.c
> > > > +++ b/drivers/usb/chipidea/core.c
> > > > @@ -518,7 +518,7 @@ static irqreturn_t ci_irq(int irq, void
> > > > *data)
> > > >  		disable_irq_nosync(irq);
> > > >  		ci->wakeup_int = true;
> > > >  		pm_runtime_get(ci->dev);
> > > > -		return IRQ_HANDLED;
> > > > +		ret = IRQ_HANDLED;
> > > >  	}
> > > >  
> > > >  	if (ci->is_otg) {
> > > > -- 
> > > > 2.27.0
> > > >