diff options
Diffstat (limited to 'kernels/linux-libre-rt/3.4.4-fix-backlight-regression.patch')
| -rw-r--r-- | kernels/linux-libre-rt/3.4.4-fix-backlight-regression.patch | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernels/linux-libre-rt/3.4.4-fix-backlight-regression.patch b/kernels/linux-libre-rt/3.4.4-fix-backlight-regression.patch new file mode 100644 index 000000000..a0cf0b1db --- /dev/null +++ b/kernels/linux-libre-rt/3.4.4-fix-backlight-regression.patch @@ -0,0 +1,38 @@ +Subject: Still use ACPI backlight control if _DOS doesn't exist + +This is a regression introduced by commit +ea9f8856bd6d4ed45885b06a338f7362cd6c60e5 + +https://bugzilla.kernel.org/show_bug.cgi?id=43168 + +Some platforms don't have _DOS control method, but the ACPI +backlight still works. +We do not want to lose the backlight control ability on these platforms. + +CC : Igor Murzov <intergalactic.anonymous@gmail.com> +Signed-off-by: Zhang Rui <rui.zhang@intel.com> +--- + drivers/acpi/video.c | 10 ++++++++-- + 1 file changed, 8 insertions(+), 2 deletions(-) + +Index: rtd3/drivers/acpi/video.c +=================================================================== +--- rtd3.orig/drivers/acpi/video.c ++++ rtd3/drivers/acpi/video.c +@@ -565,8 +565,14 @@ acpi_video_bus_DOS(struct acpi_video_bus + video->dos_setting = arg0.integer.value; + status = acpi_evaluate_object(video->device->handle, "_DOS", + &args, NULL); +- if (ACPI_FAILURE(status)) +- return -EIO; ++ if (ACPI_FAILURE(status)) { ++ /* ++ * some platforms don't have _DOS, but the ACPI ++ * backlight control still works ++ */ ++ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _DOS\n")); ++ return 0; ++ } + + return 0; + } |