On Tuesday 24 May 2016 06:48:41 Andrei Borzenkov wrote:
> 24.05.2016 02:03, Gabriele Mazzotta пишет:
> > On 24/05/2016 00:22, Pali Rohár wrote:
> >> On Tuesday 24 May 2016 00:17:15 Darren Hart wrote:
> >>> On Tue, May 24, 2016 at 12:06:03AM +0200, Pali Rohár wrote:
> >>>> On Monday 23 May 2016 23:26:55 Darren Hart wrote:
> >>>>> I've queued this. Thanks for your patience.
> >>>>
> >>>> Ok, In that case I would update comments in patch to try it more
> >>>> clear what code is doing.
> >>>
> >>> I thought I had your approval on this one Pali. Apologies if that was
> >>> not the case. Did I miss a change request from you?
> >>>
> >>> If so, please point me at it, and I'll dequeue this one and wait for
> >>> an updated one.
> >>
> >> I just wanted to review that code from somebody else and decide if
> >> accept it or not. Because I was not sure if it is OK...
> >>
> >> But there was no objection, so patch is OK.
> >>
> >> And I pointed that patch could have better comments to describe what it
> >> is doing as at first time I was confused.
> >>
> >> So I believe that you can update patch in your queue with new version
> >> which just change comments in source code (without functional changes).
> >>
> >
> > Something such as the following?
> > Feel free to reword the comments if you have something better in mind.
> >
> > ---
> > drivers/platform/x86/dell-rbtn.c | 56 ++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 56 insertions(+)
> >
> > diff --git a/drivers/platform/x86/dell-rbtn.c b/drivers/platform/x86/dell-rbtn.c
> > index 331d63c..e0208ba 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;
> > };
> >
> >
> > @@ -235,9 +236,55 @@ static const struct acpi_device_id rbtn_ids[] = {
> > { "", 0 },
> > };
> >
> > +#ifdef CONFIG_PM_SLEEP
> > +static void ACPI_SYSTEM_XFACE rbtn_acpi_clear_flag(void *context)
I would rename this function to rbtn_clear_suspended_flag.
> > +{
> > + 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;
> > +
> > + /*
> > + * Upon resume, some BIOSes autonomously send an ACPI notification
> > + * that triggers an unwanted input event. In order to ignore it,
> > + * we use a flag that we set at suspend and clear once we have
> > + * received the extra notification. Since ACPI notifications are
> > + * delivered asynchronously to drivers, we clear the flag from the
> > + * workqueue used to deliver the notifications. This should be enough
> > + * to guarantee that the flag is cleared only after we received the
> > + * extra notification, if any.
> > + */
>
> "guarantee" is rather strong word here. We really do not know anything
> how and when these notifications are generated by firmware, so can only
> hope. But otherwise this explains what this patch intends to do (so that
> even me finally understood it :)
Yes, thats better.
> > + status = acpi_os_execute(OSL_NOTIFY_HANDLER,
> > + rbtn_acpi_clear_flag, rbtn_data);
> > + if (ACPI_FAILURE(status))
> > + rbtn_data->suspended = false;
And here rbtn_clear_suspended_flag(rbtn_data) call instead direct
assignment.
> > +
> > + 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,
> > @@ -399,6 +446,15 @@ static void rbtn_notify(struct acpi_device *device, u32 event)
> > {
> > struct rbtn_data *rbtn_data = device->driver_data;
> >
> > + /*
> > + * Some BIOSes send autonomously a notification at resume.
> > + * Ignore it to prevent unwanted input events.
> > + */
> > + 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);
> >
>
--
Pali Rohár
pali.rohar@xxxxxxxxx
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