linux-kernel - Re: [PATCH v8 2/3] pinctrl: qcom: do not reinitialize gpio valid mask

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Date:   Fri,  7 Oct 2022 17:04:52 -0400
From:   Richard Acayan <mailingradian@...il.com>
To:     Bjorn Andersson <andersson@...nel.org>
Cc:     Andy Gross <agross@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Richard Acayan <mailingradian@...il.com>,
        Lee Jones <lee@...nel.org>, linux-gpio@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org, ~postmarketos/upstreaming@...ts.sr.ht
Subject: Re: [PATCH v8 2/3] pinctrl: qcom: do not reinitialize gpio valid mask

> On Thu, Oct 06, 2022 at 07:22:18PM -0400, Richard Acayan wrote:
> > It may be necessary for some devices to specify reserved gpios in the
> > device-specific DTS, in addition to the reserved gpios common to all
> > devices with a given SoC. Remove this bitmap_fill() call so that the
> > settings applied to the gpio valid mask by DTS are not overridden by
> > the driver's reserved gpios.
> > 
> > Signed-off-by: Richard Acayan <mailingradian@...il.com>
> > ---
> >  drivers/pinctrl/qcom/pinctrl-msm.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
> > index a2abfe987ab1..f697e9f64360 100644
> > --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> > +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> > @@ -687,9 +687,8 @@ static int msm_gpio_init_valid_mask(struct gpio_chip *gc,
> >  	const int *reserved = pctrl->soc->reserved_gpios;
> >  	u16 *tmp;
> >  
> > -	/* Driver provided reserved list overrides DT and ACPI */
> > +	/* Driver provided reserved list overrides other settings here */
> 
> IMHO this no longer overrides things, how about changing it to:

Technically, it doesn't. It skips the ACPI settings entirely:

	if (reserved) {
		for (i = 0; reserved[i] >= 0; i++) {
			if (i >= ngpios || reserved[i] >= ngpios) {
				dev_err(pctrl->dev, "invalid list of reserved GPIOs\n");
				return -EINVAL;
			}
			clear_bit(reserved[i], valid_mask);
		}

		return 0;
	}

	/* The number of GPIOs in the ACPI tables */
	len = ret = device_property_count_u16(pctrl->dev, "gpios");
	if (ret < 0)
		return 0;

> 
> 	/* Remove driver-provided reserved GPIOs from valid_mask */

Will do. Let me know if you think the above information changes what the comment
should be.

> 
> 
> The rest of the change looks good and the commit message looks good. So
> please consider updating the comment and feel free to add my
> 
> Reviewed-by: Bjorn Andersson <andersson@...nel.org>
> 
> Regards,
> Bjorn
> 
> >  	if (reserved) {
> > -		bitmap_fill(valid_mask, ngpios);
> >  		for (i = 0; reserved[i] >= 0; i++) {
> >  			if (i >= ngpios || reserved[i] >= ngpios) {
> >  				dev_err(pctrl->dev, "invalid list of reserved GPIOs\n");
> > -- 
> > 2.38.0
> >