Bugzilla: 1012674 Upstream-status: Queued for 3.16 From d8aceabf18681a92e8031c43d3917f6826ac6691 Mon Sep 17 00:00:00 2001 From: Hans de Goede 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 --- 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