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. [airlied: this is breaking nouveau really badly on 3.4 and after and there is no movement on sending it upstream, so please apply] Cc: Igor Murzov <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Zhang Rui <[email protected]> --- 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; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
