RE: [PATCH] gpio: gpio-pca953x: do not enable regmap cache when there is no regulator
From: Bough Chen
Date: Wed Nov 27 2024 - 20:31:21 EST
> -----Original Message-----
> From: Bartosz Golaszewski <brgl@xxxxxxxx>
> Sent: 2024年11月27日 21:05
> To: Bough Chen <haibo.chen@xxxxxxx>
> Cc: linus.walleij@xxxxxxxxxx; lgirdwood@xxxxxxxxx; broonie@xxxxxxxxxx;
> linux-gpio@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx;
> marek.vasut@xxxxxxxxx
> Subject: Re: [PATCH] gpio: gpio-pca953x: do not enable regmap cache when
> there is no regulator
>
> On Wed, Nov 27, 2024 at 8:15 AM <haibo.chen@xxxxxxx> wrote:
> >
> > From: Haibo Chen <haibo.chen@xxxxxxx>
> >
> > Regmap cache mechanism is enabled in default. Thus, IO expander
> > wouldn't handle GPIO set really before resuming back.
> >
> > But there are cases need to toggle gpio in NO_IRQ stage.
> > e.g. To align with PCIe specification, PERST# signal connected on the
> > IO expander must be toggled during PCIe RC's NO_IRQ_RESUME.
> >
> > Do not enable the regmap cache when IO expander doesn't have the
> > regulator during system PM. That means the power of IO expander would
> > be kept on, and the GPIOs of the IO expander can be toggled really during
> system PM.
> >
> > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
> > ---
>
> The commit title should be: "gpio: pca953x: ..."
>
> This description makes it sound like a fix, can you add a Fixes: tag?
Okay, will add in next version
Regards
Haibo Chen
>
> Bart