[PATCH/RFC] drm/radeon: ACPI: veto the keypress on ATIF events

Commit Message

Zhang Rui Aug. 2, 2012, 12:45 a.m. UTC

On ?, 2012-08-01 at 15:49 +0200, Luca Tettamanti wrote:
> AMD ACPI interface may overload the standard event
> ACPI_VIDEO_NOTIFY_PROBE (0x81) to signal AMD-specific events. In such
> cases we don't want to send the keypress (KEY_SWITCHVIDEOMODE) to the
> userspace because the user did not press the mode switch key (the
> spurious keypress confuses the DE which usually changes the
> display configuration and messes up a dual-screen setup).
> This patch gives the radeon driver the chance to examine the event and
> block the keypress if the event is an "AMD event".
> 
> Signed-off-by: Luca Tettamanti <[e-mail]>
> ---
> Any comment from ACPI front?
> 
it looks good to me.
But I'm wondering if we can use the following code for ACPI part, which
looks cleaner.
I know this may change the behavior of other events, but in theory, we
should not send any input event if we know something wrong in kernel.

what do you think?



>  drivers/acpi/video.c                 |   10 ++++++++--
>  drivers/gpu/drm/radeon/radeon_acpi.c |    7 ++++++-
>  2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> index 1e0a9e1..a8592c4 100644
> --- a/drivers/acpi/video.c
> +++ b/drivers/acpi/video.c
> @@ -1457,7 +1457,12 @@ static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
>  		acpi_video_device_enumerate(video);
>  		acpi_video_device_rebind(video);
>  		acpi_bus_generate_proc_event(device, event, 0);
> -		keycode = KEY_SWITCHVIDEOMODE;
> +		/* This event is also overloaded by AMD ACPI interface, don't
> +		 * send the key press if the event has been handled elsewhere
> +		 * (e.g. radeon DRM driver).
> +		 */
> +		if (!acpi_notifier_call_chain(device, event, 0))
> +			keycode = KEY_SWITCHVIDEOMODE;
>  		break;
>  
>  	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
> @@ -1479,7 +1484,8 @@ static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
>  		break;
>  	}
>  
> -	if (event != ACPI_VIDEO_NOTIFY_SWITCH)
> +	if (event != ACPI_VIDEO_NOTIFY_SWITCH &&
> +			event != ACPI_VIDEO_NOTIFY_PROBE)
>  		acpi_notifier_call_chain(device, event, 0);
>  
>  	if (keycode) {
> diff --git a/drivers/gpu/drm/radeon/radeon_acpi.c b/drivers/gpu/drm/radeon/radeon_acpi.c
> index 96de08d..ee0d29e 100644
> --- a/drivers/gpu/drm/radeon/radeon_acpi.c
> +++ b/drivers/gpu/drm/radeon/radeon_acpi.c
> @@ -273,7 +273,12 @@ int radeon_atif_handler(struct radeon_device *rdev,
>  	}
>  	/* TODO: check other events */
>  
> -	return NOTIFY_OK;
> +	/* We've handled the event, stop the notifier chain. The ACPI interface
> +	 * overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
> +	 * userspace if the event was generated only to signal a SBIOS
> +	 * request.
> +	 */
> +	return NOTIFY_BAD;
>  }
>  
>  /* Call all ACPI methods here */

Patch

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 1e0a9e1..8ad1f53 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1448,8 +1448,7 @@  static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
 	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
 					 * most likely via hotkey. */
 		acpi_bus_generate_proc_event(device, event, 0);
-		if (!acpi_notifier_call_chain(device, event, 0))
-			keycode = KEY_SWITCHVIDEOMODE;
+		keycode = KEY_SWITCHVIDEOMODE;
 		break;
 
 	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
@@ -1479,8 +1478,8 @@  static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
 		break;
 	}
 
-	if (event != ACPI_VIDEO_NOTIFY_SWITCH)
-		acpi_notifier_call_chain(device, event, 0);
+	if (acpi_notifier_call_chain(device, event, 0))
+		keycode = 0;
 
 	if (keycode) {
 		input_report_key(input, keycode, 1);