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From: Linus Walleij <linus.walleij@linaro.org>
Date: Sun, 28 Jan 2024 01:12:50 +0100
Message-ID: <CACRpkdYUVbFoDq91uLbUy8twtG_AiD+CY2+nqzCyHV7ZyBC3sA@mail.gmail.com>
Subject: Re: [PATCH 01/14] gpio: pca953x: move suspend/resume to suspend_noirq/resume_noirq
To: Thomas Richard <thomas.richard@bootlin.com>
Cc: Tony Lindgren <tony@atomide.com>, Bartosz Golaszewski <brgl@bgdev.pl>, Andy Shevchenko <andy@kernel.org>, 
	Haojian Zhuang <haojian.zhuang@linaro.org>, Vignesh R <vigneshr@ti.com>, 
	Aaro Koskinen <aaro.koskinen@iki.fi>, Janusz Krzysztofik <jmkrzyszt@gmail.com>, 
	Andi Shyti <andi.shyti@kernel.org>, Peter Rosin <peda@axentia.se>, Vinod Koul <vkoul@kernel.org>, 
	Kishon Vijay Abraham I <kishon@kernel.org>, Philipp Zabel <p.zabel@pengutronix.de>, 
	Tom Joseph <tjoseph@cadence.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, 
	=?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>, 
	Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>, linux-gpio@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
	linux-omap@vger.kernel.org, linux-i2c@vger.kernel.org, 
	linux-phy@lists.infradead.org, linux-pci@vger.kernel.org, 
	gregory.clement@bootlin.com, theo.lebrun@bootlin.com, 
	thomas.petazzoni@bootlin.com, u-kumar1@ti.com
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On Fri, Jan 19, 2024 at 6:01=E2=80=AFPM Thomas Richard
<thomas.richard@bootlin.com> wrote:
> On 1/16/24 08:43, Tony Lindgren wrote:
> > * Thomas Richard <thomas.richard@bootlin.com> [240115 16:16]:
> >> Some IOs can be needed during suspend_noirq/resume_noirq.
> >> So move suspend/resume callbacks to noirq.
> >
> > So have you checked that the pca953x_save_context() and restore works
> > this way? There's i2c traffic and regulators may sleep.. I wonder if
> > you instead just need to leave gpio-pca953x enabled in some cases
> > instead?
> >
>
> Yes I tested it, and it works (with my setup).
> But this patch may have an impact for other people.
> How could I leave it enabled in some cases ?

I guess you could define both pca953x_suspend() and
pca953x_suspend_noirq() and selectively bail out on one
path on some systems?

Worst case using if (of_machine_is_compatible("my,machine"))...

Yours,
Linus Walleij