kernel/acer-wmi-Switch-to-acpi_video_unregister_backlight.patch
Justin M. Forbes fd469c7db4 Linux v3.15.2
2014-06-30 14:20:50 -05:00

65 lines
2.6 KiB
Diff

Bugzilla: 1012674
Upstream-status: Queued for 3.16
From d8aceabf18681a92e8031c43d3917f6826ac6691 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Mon, 2 Jun 2014 17:41:05 +0200
Subject: [PATCH 08/14] acer-wmi: Switch to acpi_video_unregister_backlight
Switch from acpi_video_unregister(), to acpi_video_unregister_backlight(),
so that the hotkeys handler registered by acpi-video stays in place.
Since there are no mappings for the atkbd raw codes for the brightness
keys used by newer Acer models in /lib/udev/hwdb.d/60-keyboard.hwdb, and
since we map the wmi events with a code of KE_IGNORE, we rely on acpi-video
to do the hotkey handling for us.
For laptops such as the Acer Aspire 5750 which uses intel gfx this works
despite us calling acpi_video_unregister() because the following happens:
1) acpi-video module gets loaded (as it is a dependency of acer-wmi and i915)
2) acpi-video does NOT call acpi_video_register()
3) acer-wmi loads (assume it loads before i915), calls
acpi_video_dmi_promote_vendor(); which sets ACPI_VIDEO_BACKLIGHT_DMI_VENDOR
4) calls acpi_video_unregister -> not registered, nop
5) i915 loads, calls acpi_video_register
6) acpi_video_register registers the acpi_notifier for the hotkeys,
does NOT register a backlight device because of ACPI_VIDEO_BACKLIGHT_DMI_VENDOR
But on the Acer Aspire 5750G, which uses nvidia graphics the following happens:
1) acpi-video module gets loaded (as it is a dependency of acer-wmi)
2) acpi-video calls acpi_video_register()
3) acpi_video_register registers the acpi_notifier for the hotkeys,
and a backlight device
4) acer-wmi loads, calls acpi_video_dmi_promote_vendor()
5) calls acpi_video_unregister, this unregisters BOTH the acpi_notifier for
the hotkeys AND the backlight device
And we end up without any handler for the brightness hotkeys. This patch fixes
this by switching over to acpi_video_unregister_backlight() which keeps the
hotkey handler in place.
https://bugzilla.kernel.org/show_bug.cgi?id=35622
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/acer-wmi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index c91f69b39db4..3a746998f92a 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -2228,7 +2228,7 @@ static int __init acer_wmi_init(void)
pr_info("Brightness must be controlled by acpi video driver\n");
} else {
pr_info("Disabling ACPI video driver\n");
- acpi_video_unregister();
+ acpi_video_unregister_backlight();
}
if (wmi_has_guid(WMID_GUID3)) {
--
1.9.0