Re: [PATCH RFC] gpiolib: ensure that fwnode is properly set

[Shazad Hussain]

On 11/15/2022 2:32 AM, Robert Marko wrote:
> On 14. 11. 2022. 21:29, Brian Masney wrote:
> > Note that this is a RFC patch and not meant to be merged. I looked into
> > a problem with linux-next-20221110 on the Qualcomm SA8540P automotive
> > board (sc8280xp) where the UFS host controller would fail to probe due
> > to repeated probe deferrals when trying to get reset-gpios via
> > devm_gpiod_get_optional().
> >
> > of_get_named_gpiod_flags() returns -EPROBE_DEFER, which is caused by
> > of_gpiochip_match_node_and_xlate() returning 0 since the of_xlate 
> > function
> > pointer is not set for the qcom,sc8280xp-tlmm pinctrl driver. The
> > pinctrl driver doesn't define one, so of_gpiochip_add() should
> > automatically setup of_gpio_simple_xlate() on it's behalf. This doesn't
> > happen since the fwnode member on the struct gpiochip is set to null
> > when of_gpiochip_add() is called. Let's work around this by ensuring
> > that it's set if available.
> >
> > Note that this broke sometime within the last few weeks within
> > linux-next and I haven't bisected this. I'm posting this in the hopes
> > that someone may know offhand which patch(es) may have broken this.
>
> Hi, the following patch should fix it for you, I have hit the same issue on
> IPQ8074.
>
> https://patchwork.ozlabs.org/project/linux-gpio/patch/20221111113732.461881-1-thierry.reding@xxxxxxxxx/
This fixes the issue I was facing for sa8540p (sc8280xp). Thanks Robert.

Shazad

> Regards,
> Robert
>
> > Signed-off-by: Brian Masney <bmasney@xxxxxxxxxx>
> > ---
> >   drivers/gpio/gpiolib.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > index 11fb7ec883e9..8bec66008869 100644
> > --- a/drivers/gpio/gpiolib.c
> > +++ b/drivers/gpio/gpiolib.c
> > @@ -678,7 +678,7 @@ int gpiochip_add_data_with_key(struct gpio_chip 
> > *gc, void *data,
> >        * Assign fwnode depending on the result of the previous calls,
> >        * if none of them succeed, assign it to the parent's one.
> >        */
> > -    gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
> > +    gc->fwnode = gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
> >       gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
> >       if (gdev->id < 0) {