On Sat, Nov 29, 2014 at 09:01:47PM +0800, Aaron Lu wrote: > On 11/29/2014 01:18 AM, Brian Norris wrote: > > On Fri, Nov 28, 2014 at 07:55:00PM +0800, Aaron Lu wrote: > >> On 11/28/2014 05:59 PM, Brian Norris wrote: > >>> Do you need any additional info to handle the regression, or should we > >>> just revert the patch? > >> > >> Please attach acpidump, dmesg with video.dyndbg="module video +pft" in > >> kernel cmdline, list the /sys/class/backlight with and without this > >> commit, thanks. [...] > > Before reverting: > > > > $ ls -al /sys/class/backlight > > total 0 > > drwxr-xr-x 2 root root 0 Nov 28 09:01 . > > drwxr-xr-x 58 root root 0 Nov 28 09:01 .. > > > > After reverting: > > > > $ ls -al /sys/class/backlight > > total 0 > > drwxr-xr-x 2 root root 0 Nov 28 09:10 . > > drwxr-xr-x 50 root root 0 Nov 28 09:10 .. > > lrwxrwxrwx 1 root root 0 Nov 28 09:09 acpi_video0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 > > The current logic to bind device doesn't work with your system, that > logic is there for a long time so I prefer not to change that, instead, > I can change the newly added function acpi_video_device_in_dod to let it > directly compare the 0-12 bits of the ID to decide if the video output > device is in the _DOD list. Can you please try the following patch? > > diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c > index 41e6b977ceb2..185a57d13723 100644 > --- a/drivers/acpi/video.c > +++ b/drivers/acpi/video.c > @@ -1164,7 +1164,8 @@ static bool acpi_video_device_in_dod(struct acpi_video_device *device) > return true; > > for (i = 0; i < video->attached_count; i++) { > - if (video->attached_array[i].bind_info == device) > + if ((video->attached_array[i].value.int_val & 0xfff) == > + (device->device_id & 0xfff)) > return true; > } Thanks for the patch! This works better for me: $ ls -al /sys/class/backlight/ total 0 drwxr-xr-x 2 root root 0 Nov 29 09:00 . drwxr-xr-x 50 root root 0 Nov 29 09:00 .. lrwxrwxrwx 1 root root 0 Nov 29 08:59 acpi_video0 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 And I see no dmesg dev_dbg() prints from the acpi/video module. Tested-by: Brian Norris <computersforpeace@xxxxxxxxx> Should we try to get this into 3.18, then? Thanks, Brian -- 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