linux-kernel - Re: [PATCH v2] dell-rbtn: Ignore ACPI notifications if device is suspended

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Message-ID: <20160314114525.GK8413@pali>
Date:	Mon, 14 Mar 2016 12:45:25 +0100
From:	Pali Rohár <pali.rohar@...il.com>
To:	Gabriele Mazzotta <gabriele.mzt@...il.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Andrei Borzenkov <arvidjaar@...il.com>
Cc:	"D. Jared Dominguez" <Jared_Dominguez@...l.com>,
	"platform-driver-x86@...r.kernel.org" 
	<platform-driver-x86@...r.kernel.org>,
	Alex Hung <alex.hung@...onical.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] dell-rbtn: Ignore ACPI notifications if device is
 suspended

On Monday 14 March 2016 12:34:31 Gabriele Mazzotta wrote:
> 2016-03-12 0:49 GMT+01:00 Gabriele Mazzotta <gabriele.mzt@...il.com>:
> > Some BIOSes unconditionally send an ACPI notification to RBTN when the
> > system is resuming from suspend. This makes dell-rbtn send an input
> > event to userspace as if a function key was pressed. Prevent this by
> > ignoring all the notifications received while the device is suspended.
> >
> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=106031
> > Signed-off-by: Gabriele Mazzotta <gabriele.mzt@...il.com>
> > ---
> >  drivers/platform/x86/dell-rbtn.c | 41 ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 41 insertions(+)
> >
> > diff --git a/drivers/platform/x86/dell-rbtn.c b/drivers/platform/x86/dell-rbtn.c
> > index cd410e3..56b0da7 100644
> > --- a/drivers/platform/x86/dell-rbtn.c
> > +++ b/drivers/platform/x86/dell-rbtn.c
> > @@ -28,6 +28,7 @@ struct rbtn_data {
> >         enum rbtn_type type;
> >         struct rfkill *rfkill;
> >         struct input_dev *input_dev;
> > +       bool suspended;
> >  };
> >
> >
> > @@ -220,9 +221,44 @@ static const struct acpi_device_id rbtn_ids[] = {
> >         { "", 0 },
> >  };
> >
> > +#ifdef CONFIG_PM_SLEEP
> > +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *context)
> > +{
> > +       struct rbtn_data *rbtn_data = context;
> > +
> > +       rbtn_data->suspended = false;
> > +}
> > +
> > +static int rbtn_suspend(struct device *dev)
> > +{
> > +       struct acpi_device *device = to_acpi_device(dev);
> > +       struct rbtn_data *rbtn_data = acpi_driver_data(device);
> > +
> > +       rbtn_data->suspended = true;
> > +
> > +       return 0;
> > +}
> > +
> > +static int rbtn_resume(struct device *dev)
> > +{
> > +       struct acpi_device *device = to_acpi_device(dev);
> > +       struct rbtn_data *rbtn_data = acpi_driver_data(device);
> > +       acpi_status status;
> > +
> > +       status = acpi_os_execute(OSL_NOTIFY_HANDLER,
> > +                        rbtn_acpi_clear_flag, rbtn_data);
> > +       if (ACPI_FAILURE(status))
> > +               rbtn_data->suspended = false;
> > +
> > +       return 0;
> > +}
> > +#endif
> > +static SIMPLE_DEV_PM_OPS(rbtn_pm_ops, rbtn_suspend, rbtn_resume);
> > +
> >  static struct acpi_driver rbtn_driver = {
> >         .name = "dell-rbtn",
> >         .ids = rbtn_ids,
> > +       .drv.pm = &rbtn_pm_ops,
> >         .ops = {
> >                 .add = rbtn_add,
> >                 .remove = rbtn_remove,
> > @@ -384,6 +420,11 @@ static void rbtn_notify(struct acpi_device *device, u32 event)
> >  {
> >         struct rbtn_data *rbtn_data = device->driver_data;
> >
> > +       if (rbtn_data->suspended) {
> > +               dev_dbg(&device->dev, "ACPI notification ignored\n");
> > +               return;
> > +       }
> > +
> >         if (event != 0x80) {
> >                 dev_info(&device->dev, "Received unknown event (0x%x)\n",
> >                          event);
> > --
> > 2.7.0
> >
> 
> I'm sorry, Pali, I must have missed your email address while sending
> this updated version.

For me patch looks OK. I would suggest to add some comment about BIOS
into code too.

Rafael, can you review that ACPI suspended/OSL_NOTIFY_HANDLER part?

Andrei, can you test if it now really fix it on your machine?

-- 
Pali Rohár
pali.rohar@...il.com