On 12/15/2014 05:02 PM, Jani Nikula wrote: > On Mon, 15 Dec 2014, Aaron Lu <aaron.lu@xxxxxxxxx> wrote: >> If the firmware has declared more than 8 video output devices, and the >> one that control the internal panel's backlight is listed after the >> first 8 output devices, the _DOD will not include it due to the current >> i915 operation region implementation. As a result, we will not create a >> backlight device for it while we should. Solve this problem by special >> case the firmware that has 8+ output devices in that if we see such a >> firmware, we do not test if the device is in _DOD list. The creation of >> the backlight device will also enable the firmware to emit events on >> backlight hotkey press when the acpi_osi= cmdline option is specified on >> those affected ASUS laptops. >> >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=70241 >> Reported-and-tested-by: Oleksij Rempel <linux@xxxxxxxxxxxxxxxx> >> Reported-and-tested-by: Dmitry Tunin <hanipouspilot@xxxxxxxxx> >> Reported-and-tested-by: Jimbo <jaime.91@xxxxxxxxxx> >> Cc: stable@xxxxxxxxxxxxxxx >> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> > > Obviously I'd like to have the proper information in the opregion > DIDL/CADL fields, but it's not going to happen soon, nor is it going to > fit under stable size limits. > > I like the simplicity here. FWIW, > > Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> Thanks :-) BTW, this patch is more of a fix for my previous commit 0b8db271f159 ("ACPI / video: check _DOD list when creating backlight devices") that made the acpi_video interface disappear on these affected laptops so I would like to fix it quickly. And I agree that a proper implementation of the DIDL/CADL list is needed so that people can get rid of the acpi_osi= cmdline option they currently need to get hotkey events. Regards, Aaron > >> --- >> drivers/acpi/video.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c >> index 8b844931b936..c72e79d2c5ad 100644 >> --- a/drivers/acpi/video.c >> +++ b/drivers/acpi/video.c >> @@ -155,6 +155,7 @@ struct acpi_video_bus { >> u8 dos_setting; >> struct acpi_video_enumerated_device *attached_array; >> u8 attached_count; >> + u8 child_count; >> struct acpi_video_bus_cap cap; >> struct acpi_video_bus_flags flags; >> struct list_head video_device_list; >> @@ -1176,8 +1177,12 @@ static bool acpi_video_device_in_dod(struct acpi_video_device *device) >> struct acpi_video_bus *video = device->video; >> int i; >> >> - /* If we have a broken _DOD, no need to test */ >> - if (!video->attached_count) >> + /* >> + * If we have a broken _DOD or we have more than 8 output devices >> + * under the graphics controller node that we can't proper deal with >> + * in the operation region code currently, no need to test. >> + */ >> + if (!video->attached_count || video->child_count > 8) >> return true; >> >> for (i = 0; i < video->attached_count; i++) { >> @@ -1430,6 +1435,7 @@ acpi_video_bus_get_devices(struct acpi_video_bus *video, >> dev_err(&dev->dev, "Can't attach device\n"); >> break; >> } >> + video->child_count++; >> } >> return status; >> } >> -- >> 2.1.0 >> > -- 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
