From 2600bfa3df9944562d43d1f17016832a6ffa3b38 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 15 Apr 2022 13:59:48 +0200 Subject: ACPI: video: Add acpi_video_backlight_use_native() helper ATM on x86 laptops where we want userspace to use the acpi_video backlight device we often register both the GPU's native backlight device and acpi_video's firmware acpi_video# backlight device. This relies on userspace preferring firmware type backlight devices over native ones, but registering 2 backlight devices for a single display really is undesirable. On x86 laptops where the native GPU backlight device should be used, the registering of other backlight devices is avoided by their drivers using acpi_video_get_backlight_type() and only registering their backlight if the return value matches their type. acpi_video_get_backlight_type() uses backlight_device_get_by_type(BACKLIGHT_RAW) to determine if a native driver is available and will never return native if this returns false. This means that the GPU's native backlight registering code cannot just call acpi_video_get_backlight_type() to determine if it should register its backlight, since acpi_video_get_backlight_type() will never return native until the native backlight has already registered. To fix this add a new internal native function parameter to acpi_video_get_backlight_type(), which when set to true will make acpi_video_get_backlight_type() behave as if a native backlight has already been registered. And add a new acpi_video_backlight_use_native() helper, which sets this to true, for use in native GPU backlight code. Changes in v2: - Replace adding a native parameter to acpi_video_get_backlight_type() with adding a new acpi_video_backlight_use_native() helper. Acked-by: Rafael J. Wysocki Signed-off-by: Hans de Goede --- include/acpi/video.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/acpi') diff --git a/include/acpi/video.h b/include/acpi/video.h index db8548ff03ce..4705e339c252 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -56,6 +56,7 @@ extern void acpi_video_unregister(void); extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); extern enum acpi_backlight_type acpi_video_get_backlight_type(void); +extern bool acpi_video_backlight_use_native(void); extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type); /* * Note: The value returned by acpi_video_handles_brightness_key_presses() @@ -77,6 +78,10 @@ static inline enum acpi_backlight_type acpi_video_get_backlight_type(void) { return acpi_backlight_vendor; } +static inline bool acpi_video_backlight_use_native(void) +{ + return true; +} static inline void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) { } -- cgit v1.2.3 From 3dbc80a3e4c55c4a5b89ef207bed7b7de36157b4 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Thu, 28 Apr 2022 17:41:46 +0200 Subject: ACPI: video: Make backlight class device registration a separate step (v2) On x86/ACPI boards the acpi_video driver will usually initialize before the kms driver (except i915). This causes /sys/class/backlight/acpi_video0 to show up and then the kms driver registers its own native backlight device after which the drivers/acpi/video_detect.c code unregisters the acpi_video0 device (when acpi_video_get_backlight_type()==native). This means that userspace briefly sees 2 devices and the disappearing of acpi_video0 after a brief time confuses the systemd backlight level save/restore code, see e.g.: https://bbs.archlinux.org/viewtopic.php?id=269920 To fix this make backlight class device registration a separate step done by a new acpi_video_register_backlight() function. The intend is for this to be called by the drm/kms driver *after* it is done setting up its own native backlight device. So that acpi_video_get_backlight_type() knows if a native backlight will be available or not at acpi_video backlight registration time, avoiding the add + remove dance. Note the new acpi_video_register_backlight() function is also called from a delayed work to ensure that the acpi_video backlight devices does get registered if necessary even if there is no drm/kms driver or when it is disabled. Changes in v2: - Make register_backlight_delay a module parameter, mainly so that it can be disabled by Nvidia binary driver users Acked-by: Rafael J. Wysocki Signed-off-by: Hans de Goede --- drivers/acpi/acpi_video.c | 50 ++++++++++++++++++++++++++++++++++++++++++++--- include/acpi/video.h | 2 ++ 2 files changed, 49 insertions(+), 3 deletions(-) (limited to 'include/acpi') diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 8545bf94866f..09dd86f86cf3 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -73,6 +73,16 @@ module_param(device_id_scheme, bool, 0444); static int only_lcd = -1; module_param(only_lcd, int, 0444); +/* + * Display probing is known to take up to 5 seconds, so delay the fallback + * backlight registration by 5 seconds + 3 seconds for some extra margin. + */ +static int register_backlight_delay = 8; +module_param(register_backlight_delay, int, 0444); +MODULE_PARM_DESC(register_backlight_delay, + "Delay in seconds before doing fallback (non GPU driver triggered) " + "backlight registration, set to 0 to disable."); + static bool may_report_brightness_keys; static int register_count; static DEFINE_MUTEX(register_count_mutex); @@ -81,6 +91,9 @@ static LIST_HEAD(video_bus_head); static int acpi_video_bus_add(struct acpi_device *device); static int acpi_video_bus_remove(struct acpi_device *device); static void acpi_video_bus_notify(struct acpi_device *device, u32 event); +static void acpi_video_bus_register_backlight_work(struct work_struct *ignored); +static DECLARE_DELAYED_WORK(video_bus_register_backlight_work, + acpi_video_bus_register_backlight_work); void acpi_video_detect_exit(void); /* @@ -1859,8 +1872,6 @@ static int acpi_video_bus_register_backlight(struct acpi_video_bus *video) if (video->backlight_registered) return 0; - acpi_video_run_bcl_for_osi(video); - if (acpi_video_get_backlight_type() != acpi_backlight_video) return 0; @@ -2086,7 +2097,11 @@ static int acpi_video_bus_add(struct acpi_device *device) list_add_tail(&video->entry, &video_bus_head); mutex_unlock(&video_list_lock); - acpi_video_bus_register_backlight(video); + /* + * The userspace visible backlight_device gets registered separately + * from acpi_video_register_backlight(). + */ + acpi_video_run_bcl_for_osi(video); acpi_video_bus_add_notify_handler(video); return 0; @@ -2125,6 +2140,11 @@ static int acpi_video_bus_remove(struct acpi_device *device) return 0; } +static void acpi_video_bus_register_backlight_work(struct work_struct *ignored) +{ + acpi_video_register_backlight(); +} + static int __init is_i740(struct pci_dev *dev) { if (dev->device == 0x00D1) @@ -2235,6 +2255,18 @@ int acpi_video_register(void) */ register_count = 1; + /* + * acpi_video_bus_add() skips registering the userspace visible + * backlight_device. The intend is for this to be registered by the + * drm/kms driver calling acpi_video_register_backlight() *after* it is + * done setting up its own native backlight device. The delayed work + * ensures that acpi_video_register_backlight() always gets called + * eventually, in case there is no drm/kms driver or it is disabled. + */ + if (register_backlight_delay) + schedule_delayed_work(&video_bus_register_backlight_work, + register_backlight_delay * HZ); + leave: mutex_unlock(®ister_count_mutex); return ret; @@ -2245,6 +2277,7 @@ void acpi_video_unregister(void) { mutex_lock(®ister_count_mutex); if (register_count) { + cancel_delayed_work_sync(&video_bus_register_backlight_work); acpi_bus_unregister_driver(&acpi_video_bus); register_count = 0; may_report_brightness_keys = false; @@ -2253,6 +2286,17 @@ void acpi_video_unregister(void) } EXPORT_SYMBOL(acpi_video_unregister); +void acpi_video_register_backlight(void) +{ + struct acpi_video_bus *video; + + mutex_lock(&video_list_lock); + list_for_each_entry(video, &video_bus_head, entry) + acpi_video_bus_register_backlight(video); + mutex_unlock(&video_list_lock); +} +EXPORT_SYMBOL(acpi_video_register_backlight); + void acpi_video_unregister_backlight(void) { struct acpi_video_bus *video; diff --git a/include/acpi/video.h b/include/acpi/video.h index 4705e339c252..0625806d3bbd 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -53,6 +53,7 @@ enum acpi_backlight_type { #if IS_ENABLED(CONFIG_ACPI_VIDEO) extern int acpi_video_register(void); extern void acpi_video_unregister(void); +extern void acpi_video_register_backlight(void); extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); extern enum acpi_backlight_type acpi_video_get_backlight_type(void); @@ -69,6 +70,7 @@ extern int acpi_video_get_levels(struct acpi_device *device, #else static inline int acpi_video_register(void) { return -ENODEV; } static inline void acpi_video_unregister(void) { return; } +static inline void acpi_video_register_backlight(void) { return; } static inline int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid) { -- cgit v1.2.3 From fe7aebb40d42bf8e830019d6f57c47cf7d85aa61 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 4 Jun 2022 14:06:18 +0200 Subject: ACPI: video: Add Nvidia WMI EC brightness control detection (v3) On some new laptop designs a new Nvidia specific WMI interface is present which gives info about panel brightness control and may allow controlling the brightness through this interface when the embedded controller is used for brightness control. When this WMI interface is present and indicates that the EC is used, then this interface should be used for brightness control. Changes in v2: - Use the new shared nvidia-wmi-ec-backlight.h header for the WMI firmware API definitions - ACPI_VIDEO can now be enabled on non X86 too, adjust the Kconfig changes to match this. Changes in v3: - Use WMI_BRIGHTNESS_GUID define Acked-by: Rafael J. Wysocki Reviewed-by: Daniel Dadap Signed-off-by: Hans de Goede --- drivers/acpi/Kconfig | 1 + drivers/acpi/video_detect.c | 37 +++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/gma500/Kconfig | 2 ++ drivers/gpu/drm/i915/Kconfig | 2 ++ include/acpi/video.h | 1 + 5 files changed, 43 insertions(+) (limited to 'include/acpi') diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 7802d8846a8d..44ad4b6bd234 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -212,6 +212,7 @@ config ACPI_VIDEO tristate "Video" depends on BACKLIGHT_CLASS_DEVICE depends on INPUT + depends on ACPI_WMI || !X86 select THERMAL help This driver implements the ACPI Extensions For Display Adapters diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index cc9d0d91e268..4dc7fb865083 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -75,6 +76,36 @@ find_video(acpi_handle handle, u32 lvl, void *context, void **rv) return AE_OK; } +/* This depends on ACPI_WMI which is X86 only */ +#ifdef CONFIG_X86 +static bool nvidia_wmi_ec_supported(void) +{ + struct wmi_brightness_args args = { + .mode = WMI_BRIGHTNESS_MODE_GET, + .val = 0, + .ret = 0, + }; + struct acpi_buffer buf = { (acpi_size)sizeof(args), &args }; + acpi_status status; + + status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0, + WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf); + if (ACPI_FAILURE(status)) + return false; + + /* + * If brightness is handled by the EC then nvidia-wmi-ec-backlight + * should be used, else the GPU driver(s) should be used. + */ + return args.ret == WMI_BRIGHTNESS_SOURCE_EC; +} +#else +static bool nvidia_wmi_ec_supported(void) +{ + return false; +} +#endif + /* Force to use vendor driver when the ACPI device is known to be * buggy */ static int video_detect_force_vendor(const struct dmi_system_id *d) @@ -541,6 +572,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = { static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) { static DEFINE_MUTEX(init_mutex); + static bool nvidia_wmi_ec_present; static bool native_available; static bool init_done; static long video_caps; @@ -553,6 +585,7 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, find_video, NULL, &video_caps, NULL); + nvidia_wmi_ec_present = nvidia_wmi_ec_supported(); init_done = true; } if (native) @@ -570,6 +603,10 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) if (acpi_backlight_dmi != acpi_backlight_undef) return acpi_backlight_dmi; + /* Special cases such as nvidia_wmi_ec and apple gmux. */ + if (nvidia_wmi_ec_present) + return acpi_backlight_nvidia_wmi_ec; + /* On systems with ACPI video use either native or ACPI video. */ if (video_caps & ACPI_VIDEO_BACKLIGHT) { /* diff --git a/drivers/gpu/drm/gma500/Kconfig b/drivers/gpu/drm/gma500/Kconfig index 0cff20265f97..807b989e3c77 100644 --- a/drivers/gpu/drm/gma500/Kconfig +++ b/drivers/gpu/drm/gma500/Kconfig @@ -7,6 +7,8 @@ config DRM_GMA500 select ACPI_VIDEO if ACPI select BACKLIGHT_CLASS_DEVICE if ACPI select INPUT if ACPI + select X86_PLATFORM_DEVICES if ACPI + select ACPI_WMI if ACPI help Say yes for an experimental 2D KMS framebuffer driver for the Intel GMA500 (Poulsbo), Intel GMA600 (Moorestown/Oak Trail) and diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig index 7ae3b7d67fcf..3efce05d7b57 100644 --- a/drivers/gpu/drm/i915/Kconfig +++ b/drivers/gpu/drm/i915/Kconfig @@ -23,6 +23,8 @@ config DRM_I915 # but for select to work, need to select ACPI_VIDEO's dependencies, ick select BACKLIGHT_CLASS_DEVICE if ACPI select INPUT if ACPI + select X86_PLATFORM_DEVICES if ACPI + select ACPI_WMI if ACPI select ACPI_VIDEO if ACPI select ACPI_BUTTON if ACPI select SYNC_FILE diff --git a/include/acpi/video.h b/include/acpi/video.h index 0625806d3bbd..91578e77ac4e 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -48,6 +48,7 @@ enum acpi_backlight_type { acpi_backlight_video, acpi_backlight_vendor, acpi_backlight_native, + acpi_backlight_nvidia_wmi_ec, }; #if IS_ENABLED(CONFIG_ACPI_VIDEO) -- cgit v1.2.3 From 21245df307cbee9e04d5b4aac3fd04334f6b45dc Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 4 Jun 2022 15:21:51 +0200 Subject: ACPI: video: Add Apple GMUX brightness control detection On Apple laptops with an Apple GMUX using this for brightness control, should take precedence of any other brightness control methods. Add apple-gmux detection to acpi_video_get_backlight_type() using the already existing apple_gmux_present() helper function. This will allow removig the (ab)use of: acpi_video_set_dmi_backlight_type(acpi_backlight_vendor); Inside the apple-gmux driver. Acked-by: Rafael J. Wysocki Signed-off-by: Hans de Goede --- drivers/acpi/video_detect.c | 4 ++++ include/acpi/video.h | 1 + 2 files changed, 5 insertions(+) (limited to 'include/acpi') diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 4dc7fb865083..be2fc43418af 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -28,6 +28,7 @@ #include #include +#include #include #include #include @@ -607,6 +608,9 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) if (nvidia_wmi_ec_present) return acpi_backlight_nvidia_wmi_ec; + if (apple_gmux_present()) + return acpi_backlight_apple_gmux; + /* On systems with ACPI video use either native or ACPI video. */ if (video_caps & ACPI_VIDEO_BACKLIGHT) { /* diff --git a/include/acpi/video.h b/include/acpi/video.h index 91578e77ac4e..dbd48cb8bd23 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -49,6 +49,7 @@ enum acpi_backlight_type { acpi_backlight_vendor, acpi_backlight_native, acpi_backlight_nvidia_wmi_ec, + acpi_backlight_apple_gmux, }; #if IS_ENABLED(CONFIG_ACPI_VIDEO) -- cgit v1.2.3 From 77ab9d4d44cd235322d2f30b1c4026302c3ce8c6 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 20 Jun 2022 11:49:57 +0200 Subject: ACPI: video: Remove acpi_video_set_dmi_backlight_type() acpi_video_set_dmi_backlight_type() is troublesome because it may end up getting called after other backlight drivers have already called acpi_video_get_backlight_type() resulting in the other drivers already being registered even though they should not. In case of the acpi_video backlight, acpi_video_set_dmi_backlight_type() actually calls acpi_video_unregister_backlight() since that is often probed earlier, leading to userspace seeing the acpi_video0 class device being briefly available, leading to races in userspace where udev probe-rules try to access the device and it is already gone. All callers have been fixed to no longer call it, so remove acpi_video_set_dmi_backlight_type() now. This means we now also no longer need acpi_video_unregister_backlight() for the remove acpi_video backlight after it was wrongly registered hack, so remove that too. Acked-by: Rafael J. Wysocki Signed-off-by: Hans de Goede --- drivers/acpi/acpi_video.c | 10 ---------- drivers/acpi/video_detect.c | 16 ---------------- include/acpi/video.h | 4 ---- 3 files changed, 30 deletions(-) (limited to 'include/acpi') diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index d1e41f30c004..a7c3d11e0dac 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -2296,16 +2296,6 @@ void acpi_video_register_backlight(void) } EXPORT_SYMBOL(acpi_video_register_backlight); -void acpi_video_unregister_backlight(void) -{ - struct acpi_video_bus *video; - - mutex_lock(&video_list_lock); - list_for_each_entry(video, &video_bus_head, entry) - acpi_video_bus_unregister_backlight(video); - mutex_unlock(&video_list_lock); -} - bool acpi_video_handles_brightness_key_presses(void) { return may_report_brightness_keys && diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 3861d4121172..67a0211c07b4 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -38,8 +38,6 @@ #include #include -void acpi_video_unregister_backlight(void); - static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef; static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef; @@ -817,17 +815,3 @@ bool acpi_video_backlight_use_native(void) return __acpi_video_get_backlight_type(true) == acpi_backlight_native; } EXPORT_SYMBOL(acpi_video_backlight_use_native); - -/* - * Set the preferred backlight interface type based on DMI info. - * This function allows DMI blacklists to be implemented by external - * platform drivers instead of putting a big blacklist in video_detect.c - */ -void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) -{ - acpi_backlight_dmi = type; - /* Remove acpi-video backlight interface if it is no longer desired */ - if (acpi_video_get_backlight_type() != acpi_backlight_video) - acpi_video_unregister_backlight(); -} -EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type); diff --git a/include/acpi/video.h b/include/acpi/video.h index dbd48cb8bd23..a275c35e5249 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -60,7 +60,6 @@ extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); extern enum acpi_backlight_type acpi_video_get_backlight_type(void); extern bool acpi_video_backlight_use_native(void); -extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type); /* * Note: The value returned by acpi_video_handles_brightness_key_presses() * may change over time and should not be cached. @@ -86,9 +85,6 @@ static inline bool acpi_video_backlight_use_native(void) { return true; } -static inline void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) -{ -} static inline bool acpi_video_handles_brightness_key_presses(void) { return false; -- cgit v1.2.3