Bug 15662

Summary:	Double brightness key event on Dell Vostro 1320
Product:	ACPI	Reporter:	Felix Geyer (debfx-kernel)
Component:	Power-Video	Assignee:	Zhang Rui (rui.zhang)
Status:	REJECTED WILL_NOT_FIX
Severity:	normal	CC:	mjg59-kernel, rui.zhang
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.32.10	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	Output of: grep . /sys/class/input/input/ read-input-event output on /dev/input/event5 read-input-event output on /dev/input/event6 Output of acpidump

Description Felix Geyer 2010-03-31 20:59:53 UTC

The brightness keys don't work with KMS.
With the patch from https://bugzilla.kernel.org/show_bug.cgi?id=15054#c23 the keys work again but the brightness key events are emitted twice.

Comment 1 Felix Geyer 2010-03-31 21:04:09 UTC

Created attachment 25780 [details]
Output of: grep . /sys/class/input/input*/*

Comment 2 Felix Geyer 2010-03-31 21:07:11 UTC

Created attachment 25781 [details]
read-input-event output on /dev/input/event5

as requested in https://bugzilla.kernel.org/show_bug.cgi?id=15054#c32

Comment 3 Felix Geyer 2010-03-31 21:08:09 UTC

Created attachment 25782 [details]
read-input-event output on /dev/input/event6

Comment 4 Matthew Garrett 2010-04-01 14:12:18 UTC

Dell are sending the event via both the keyboard controller and ACPI. Can you attach the output of the acpidump command?

Comment 5 Felix Geyer 2010-04-01 16:43:49 UTC

Created attachment 25801 [details]
Output of acpidump

Comment 6 Felix Geyer 2010-04-19 09:24:12 UTC

Is there any more debug data you need?

Comment 7 Zhang Rui 2010-05-11 07:46:13 UTC

The hotkey works well in KMS mode, right?
                    Method (_Q11, 0, NotSerialized)
                    {
                        Store (0x87, P80H)
                        If (IGDS)
                        {
                            ^^^GFX0.BRTN (0x87)
                        }
                        Else
                        {
                            Notify (^^^P0P2.VGA.LCD, 0x87)
                        }
                    }

notification is sent to ACPI video device only if IGDS is not set by BIOS, which seems to be true on this laptop.
As IGDS stands for the IGD Opregion stuff which is supported by KMS only, I'm wondering why you want KMS disabled.

Comment 8 Felix Geyer 2010-05-11 08:56:28 UTC

No, it doesn't work well with KMS.

With kernel 2.6.34 rc7 it doesn't matter if KMS is enabled or not, the brightness key events are emitted twice.

Comment 9 Zhang Rui 2010-05-20 07:27:23 UTC

I see, BTRN also sends notifications to the ACPI video device.
So, IMO, the brightness hotkey control via ACPI works pretty well, except that there is an extra interrupt to the keyboard.

sounds like a firmware problem to me.
matthew, what do you think?

Comment 10 Zhang Rui 2010-06-09 06:34:06 UTC

bug closed as this is a firmware bug that we can not fix...
maybe you need some tricks to eliminate a hotkey event in user space.