Re: [RFC][PATCH 2/2] ACPI video: Don't start video device until its associated input device has been reigstered

Dmitry Torokhov
2012-02-29T01:17:31Z

On Tue, Feb 28, 2012 at 04:39:15PM -0800, Dmitry Torokhov wrote:
> On Wed, Feb 29, 2012 at 03:55:18AM +0400, Igor Murzov wrote:
> > From 202f25d44b1cf871697c88a6a3a8d854674db4d8 Mon Sep 17 00:00:00 2001
> > From: Igor Murzov <e-mail@date.by>
> > Date: Mon, 27 Feb 2012 21:57:59 +0400
> > Subject: [PATCH 2/2] ACPI video: Don't start video device until its
> > associated input device has been reigstered
>
> >
> > ---
> > drivers/acpi/video.c | 10 ++++++----
> > 1 files changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> > index 1bc6370..b9e114c 100644
> > --- a/drivers/acpi/video.c
> > +++ b/drivers/acpi/video.c
> > @@ -1659,9 +1659,6 @@ static int acpi_video_bus_add(struct acpi_device *device)
> > error = acpi_video_bus_get_devices(video, device);
> > if (error)
> > goto err_free_video;
> > - error = acpi_video_bus_start_devices(video);
> > - if (error)
> > - goto err_put_video;
> >
> > video->input = input = input_allocate_device();
> > if (!input) {
> > @@ -1703,13 +1700,18 @@ static int acpi_video_bus_add(struct acpi_device *device)
> > if (error)
> > goto err_free_input_dev;
> >
> > + error = acpi_video_bus_start_devices(video);
> > + if (error)
> > + goto err_unregister_pm_notifier;
> > +
>
> Registered input device should be unregistered with
> input_unregister_device(), not input_free_device(). Your change breaks
> this.
>
> Also, notify() will not be called until acpi_video_bus_add() completes
> so current code should be perfectly fine.

Hm, I take the last paragraph back - in addition to bus notifier we do
install device notifier explicitly so it might fire up early. The
easiest fox would be to move acpi_video_bus_start_devices after
input_allocate_device() but before input_refister_device() -
unregistered input devoces can handle input_event() calls just fine.

--
Dmitry