Red Hat Bugzilla – Bug 856731
backlight turned off permanently on boot on hp laptop
Last modified: 2013-01-17 07:10:48 EST
Description of problem:
Moving from 3.5.2-3 to 3.5.3-1 causes the backlight on an hp dv6 to turn off on boot (plymouth starting?) and I cannot turn it back on.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Install f17 on dv6 (A6Y51UA#ABA)
2. Upgrade to 3.5.3-1
3. Boot and watch the screen go ultra black
I am stuck with 3.5.2-3 for now so that it works.
Created attachment 615007 [details]
Created attachment 615008 [details]
Sorry that I forgot to attach these before.
kernel-3.5.4-1.fc17.x86_64 does not fix it.
Sep 24 08:13:41 Shadowfax kernel: [ 41.510733] radeon 0000:00:01.0: couldn't schedule ib
Sep 24 08:13:41 Shadowfax kernel: [ 41.510741] [drm:radeon_cs_ib_chunk] *ERROR* Failed to schedule IB !
I just noticed this with 3.5.4-1. I am not sure if this is related or not. It does not seem to appear with the 3.5.2-3 which works.
Interestingly enough this only happens, it seems, if prelink isn't up to date. I am not sure what is going one. 3.5.4-1 started working after prelink. 3.5.4-2 doesn't work, but I haven't run prelink (doing so now).
If prelink changes how your backlight is behaving, that isn't a kernel issue. prelink doesn't impact the kernel at all.
I will let you know if prelink does indeed change it. It maybe screen/bios state as well. I am playing with some ideas to see what really changes it.
Ok, as I have looked at this, it appears that it must be plymouth or something else related and not kernel as prelink does seem to be the key. I don't know if it is drm driver specific or not.
Sorry for the noise. I believe this is either fixed or mostly fixed in the last F17 kernel. I didn't mean to mark this F18.