Re: [PATCH 1/8] Input: elan_i2c - Use PM subsystem to manage wake irq

Tony Lindgren
2022-09-01T06:58:09Z

* Rafael J. Wysocki <rafael@kernel.org> [220831 18:35]:
> On Wed, Aug 31, 2022 at 8:14 PM Raul Rangel <rrangel@chromium.org> wrote:
> >
> > On Wed, Aug 31, 2022 at 12:01 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > >
> > > On Wed, Aug 31, 2022 at 1:16 AM Raul E Rangel <rrangel@chromium.org> wrote:
> > > >
> > > > The Elan I2C touchpad driver is currently manually managing the wake
> > > > IRQ. This change removes the explicit enable_irq_wake/disable_irq_wake
> > > > and instead relies on the PM subsystem. This is done by calling
> > > > dev_pm_set_wake_irq.
> > > >
> > > > i2c_device_probe already calls dev_pm_set_wake_irq when using device
> > > > tree, so it's only required when using ACPI. The net result is that this
> > > > change should be a no-op. i2c_device_remove also already calls
> > > > dev_pm_clear_wake_irq, so we don't need to do that in this driver.
> > > >
> > > > I tested this on an ACPI system where the touchpad doesn't have _PRW
> > > > defined. I verified I can still wake the system and that the wake source
> > > > was the touchpad IRQ GPIO.
> > > >
> > > > Signed-off-by: Raul E Rangel <rrangel@chromium.org>
> > >
> >
> >
> > > I like this a lot, but the assumption in the wakeirq code is that the
> > > IRQ in question will be dedicated for signaling wakeup. Does it hold
> > > here?
> >
> > The wakeirq code defines two methods: `dev_pm_set_wake_irq` and
> > `dev_pm_set_dedicated_wake_irq`.
> > The latter is used when you have a dedicated wakeup signal. In this
> > driver it's currently assumed
> > that the IRQ and the wake IRQ are the same, so I used `dev_pm_set_wake_irq`.
> >
> > This change in theory also fixes a bug where you define a dedicated
> > wake irq in DT, but
> > then the driver enables the `client->irq` as a wake source. In
> > practice this doesn't happen
> > since the elan touchpads only have a single IRQ line.
>
> OK, thanks!
>
> Please feel free to add
>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> to the patch.

Looks good to me too:

Reviewed-by: Tony Lindgren <tony@atomide.com>