diff options
author | Hans de Goede <hdegoede@redhat.com> | 2022-11-14 17:44:58 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-11-16 21:52:48 +0300 |
commit | a5df42521f328b45c9d89c13740e747be08ac66e (patch) | |
tree | 15873490d1c1f0a1d13bb964434175b296ff1a80 /drivers/acpi | |
parent | f5a6ff923d4a1d639da36228d00e95ff67d417f0 (diff) | |
download | linux-a5df42521f328b45c9d89c13740e747be08ac66e.tar.xz |
ACPI: video: Simplify __acpi_video_get_backlight_type()
Simplify __acpi_video_get_backlight_type() removing a nested if which
makes the flow harder to follow.
This also results in having only 1 exit point with
return acpi_backlight_native instead of 2.
Note this drops the (video_caps & ACPI_VIDEO_BACKLIGHT) check from
the if (acpi_osi_is_win8() && native_available) return native path.
Windows 8's hardware certification requirements include that there must
be ACPI video bus backlight control, so the ACPI_VIDEO_BACKLIGHT check
is redundant.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r-- | drivers/acpi/video_detect.c | 36 |
1 files changed, 17 insertions, 19 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 0e217bf79f17..5da6b1b449d5 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -716,6 +716,16 @@ static bool google_cros_ec_present(void) } /* + * Windows 8 and newer no longer use the ACPI video interface, so it often + * does not work. So on win8+ systems prefer native brightness control. + * Chromebooks should always prefer native backlight control. + */ +static bool prefer_native_over_acpi_video(void) +{ + return acpi_osi_is_win8() || google_cros_ec_present(); +} + +/* * Determine which type of backlight interface to use on this system, * First check cmdline, then dmi quirks, then do autodetect. */ @@ -760,26 +770,14 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) if (apple_gmux_present()) return acpi_backlight_apple_gmux; - /* Chromebooks should always prefer native backlight control. */ - if (google_cros_ec_present() && native_available) - return acpi_backlight_native; + /* Use ACPI video if available, except when native should be preferred. */ + if ((video_caps & ACPI_VIDEO_BACKLIGHT) && + !(native_available && prefer_native_over_acpi_video())) + return acpi_backlight_video; - /* On systems with ACPI video use either native or ACPI video. */ - if (video_caps & ACPI_VIDEO_BACKLIGHT) { - /* - * Windows 8 and newer no longer use the ACPI video interface, - * so it often does not work. If the ACPI tables are written - * for win8 and native brightness ctl is available, use that. - * - * The native check deliberately is inside the if acpi-video - * block on older devices without acpi-video support native - * is usually not the best choice. - */ - if (acpi_osi_is_win8() && native_available) - return acpi_backlight_native; - else - return acpi_backlight_video; - } + /* Use native if available */ + if (native_available && prefer_native_over_acpi_video()) + return acpi_backlight_native; /* No ACPI video (old hw), use vendor specific fw methods. */ return acpi_backlight_vendor; |