Bug 56911

Summary: [snb] Switching to i915 cause a black screen on macbookpro 8,2
Product: Drivers Reporter: Mario (mleone87)
Component: Video(DRI - Intel)Assignee: intel-gfx-bugs (intel-gfx-bugs)
Status: RESOLVED MOVED    
Severity: normal CC: intel-gfx-bugs, lukas, mbvett, miguel.negrao, ridershome, seb.belese, stephane.travostino, tarkasteve, william
Priority: P3    
Hardware: All   
OS: Linux   
See Also: https://bugs.freedesktop.org/show_bug.cgi?id=61115
Kernel Version: 3.8.7-1-ARCH Subsystem:
Regression: No Bisected commit-id:
Attachments: DMESG

Description Mario 2013-04-20 21:33:38 UTC 
I installed arch linux with kernel 3.8.7 on my mbpro 8,2 and i boot it from EFISTUB directly from rEFInd.

These are the parameters passed to the kernel

rootflags=,relatime,data=ordered rootfstype=ext4 add_efi_memmap elevator=noop vt.handoff=7 i915.modeset=1 radeon.modeset=1 initrd=\EFI\arch\initramfs-arch.img ro

Early boot: 
cat /sys/kernel/debug/vgaswitcheroo/switch 
0:DIS:+:Pwr:0000:01:00.0
1:DIS-Audio: :Pwr:0000:01:00.1
2:IGD: :Pwr:0000:00:02.0

To get a working X server
cat /sys/kernel/debug/vgaswitcheroo/switch 
0:DIS:+:Pwr:0000:01:00.0
1:DIS-Audio: :Pwr:0000:01:00.1
2:IGD: :Off:0000:00:02.0

any combination od IGD DIGD with or without OFF/ON before and after cause a black screen, The system is fully operational, i can blindly enable radeon by passing DIS to switch and i can get the screen back!
Comment 1 Mario 2013-04-20 21:34:15 UTC 
Created attachment 99531 [details]
DMESG
Comment 2 Miguel Negrão 2013-05-31 15:03:38 UTC 
I'm affected by the same issue. Is there any possible fix for this ?
Comment 3 Willia 2013-06-02 00:19:22 UTC 
I have the same issue. According to an exchange on the rh bz https://bugzilla.redhat.com/show_bug.cgi?id=837461 what is missing is LVDS reprobe from the intel drivers.

This issue is also listed https://bugs.freedesktop.org/show_bug.cgi?id=61115

The cause appears to be that on switch, when the intel GPU is connected to the gmux, the display bus is not probed for what is now attached. Thus, the black screen as the intel tries to render to "some other display".
Comment 4 Jani Nikula 2013-11-11 12:53:57 UTC 
Have you tried 3.11 or 3.12 kernels?
Comment 5 Stephane Travostino 2013-11-27 18:55:18 UTC 
Yes, I'm experiencing the same problem on Archlinux, kernel 3.12.1.

My laptop is a Sony Vaio SA series with hardware GPU switch. The systems always starts with the Intel GPU enabled and active.
When switching to the dedicated ATI card I get a blank screen.

How may I help debug this? I'd really like to use the dedicated card, and there's no way, apart from using the proprietary Catalyst drivers, to enable the ATI card.
Comment 6 Miguel Negrão 2014-04-15 15:30:40 UTC 
I've just updated to ubuntu 14.04 beta 2, which uses kernel 3.13.0-24-lowlatency. This issue is till present. Is there any hope with this issue ? Would love not having to reboot when wanting to use an external screen... makes linux look bad in conferences and presentations... :-(
Comment 7 Thomas Berger 2014-06-05 08:01:05 UTC 
Same/similar issue here, Arch Linux, kernel 3.14.5, Thinkpad T430 (two muxless cards: NVS 5400M, Intel 4000). When I boot with the Nvidia switched on in /etc/tmpfiles.d:

w /sys/kernel/debug/vgaswitcheroo/switch - - - - DDIS
w /sys/kernel/debug/vgaswitcheroo/switch - - - - ON

the screen attached to the Intel card is black. I see in the logs "i915: switched off". After X started I can write "ON" to /sys/kernel/debug/vgaswitcheroo/switch and the screen attached to the Intel card is working.


This bug report has the status NEEDINFO. What info do you need?
Comment 9 Lukas Wunner 2015-04-23 13:45:03 UTC 
A patchset which is believed to fix this issue was posted to dri-devel:
http://lists.freedesktop.org/archives/dri-devel/2015-April/081515.html

This patchset enables GPU switching and should at least work on pre-retinas. Please apply it on top of a recent kernel and report back if it works for you.

Thank you!