On 07/07/2014 09:01 PM, Rafael J. Wysocki wrote: > On Monday, July 07, 2014 03:43:51 PM Aaron Lu wrote: >> Some Thinkpad laptops' firmware will initiate a backlight level change >> request through operation region on the events of AC plug/unplug, but >> since we are not using firmware's interface to do the backlight setting >> on these affected laptops, we do not want the firmware to use some >> arbitrary value from its ASL variable to set the backlight level on >> AC plug/unplug either. >> >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=76491 >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=77091 >> Reported-and-tested-by: Igor Gnatenko <i.gnatenko.brain@xxxxxxxxx> >> Reported-and-tested-by: Anton Gubarkov <anton.gubarkov@xxxxxxxxx> >> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> >> Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> >> --- >> v2: add a debug message when ignoring opregion request as suggested by >> Jani Nikula. >> >> drivers/acpi/video.c | 3 ++- >> drivers/gpu/drm/i915/intel_opregion.c | 9 +++++++++ >> include/acpi/video.h | 2 ++ >> 3 files changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c >> index fb9ffe9adc64..cf99d6d2d491 100644 >> --- a/drivers/acpi/video.c >> +++ b/drivers/acpi/video.c >> @@ -241,13 +241,14 @@ static bool acpi_video_use_native_backlight(void) >> return use_native_backlight_dmi; >> } >> >> -static bool acpi_video_verify_backlight_support(void) >> +bool acpi_video_verify_backlight_support(void) >> { >> if (acpi_osi_is_win8() && acpi_video_use_native_backlight() && >> backlight_device_registered(BACKLIGHT_RAW)) >> return false; >> return acpi_video_backlight_support(); >> } >> +EXPORT_SYMBOL(acpi_video_verify_backlight_support); > > Is there any reason for this not to be EXPORT_SYMBOL_GPL()? No particular reason, just follow what is used for other exported functions in this file. Will change this to EXPORT_SYMBOL_GPL. > >> /* backlight device sysfs support */ >> static int acpi_video_get_brightness(struct backlight_device *bd) >> diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c >> index 2e2c71fcc9ed..4f6b53998d79 100644 >> --- a/drivers/gpu/drm/i915/intel_opregion.c >> +++ b/drivers/gpu/drm/i915/intel_opregion.c >> @@ -403,6 +403,15 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp) >> >> DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp); >> >> + /* >> + * If the acpi_video interface is not supposed to be used, don't >> + * bother processing backlight level change requests from firmware. >> + */ >> + if (!acpi_video_verify_backlight_support()) { >> + DRM_DEBUG_KMS("opregion backlight request ignored\n"); >> + return 0; >> + } >> + >> if (!(bclp & ASLE_BCLP_VALID)) >> return ASLC_BACKLIGHT_FAILED; >> >> diff --git a/include/acpi/video.h b/include/acpi/video.h >> index ea4c7bbded4d..92f8c4bffefb 100644 >> --- a/include/acpi/video.h >> +++ b/include/acpi/video.h >> @@ -22,6 +22,7 @@ extern void acpi_video_unregister(void); >> extern void acpi_video_unregister_backlight(void); >> extern int acpi_video_get_edid(struct acpi_device *device, int type, >> int device_id, void **edid); >> +extern bool acpi_video_verify_backlight_support(void); >> #else >> static inline int acpi_video_register(void) { return 0; } >> static inline void acpi_video_unregister(void) { return; } >> @@ -31,6 +32,7 @@ static inline int acpi_video_get_edid(struct acpi_device *device, int type, >> { >> return -ENODEV; >> } >> +static bool acpi_video_verify_backlight_support() { return false; } > > And for this not to be static inline? Will add inline. Thanks for the review. -Aaron > >> #endif >> >> #endif >> > > Rafael > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html