Bug 92483

Summary: [regression] Can only go to console (fbcon/fbdev) once. Screen gets blank on console mode on next attempts.
Product: DRI Reporter: Rodrigo Vivi <rodrigo.vivi>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: CLOSED FIXED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: medium CC: daniel, intel-gfx-bugs, robclark
Version: DRI gitKeywords: bisected
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features: display/atomic
Attachments:
Description Flags
dmesg none

Description Rodrigo Vivi 2015-10-15 22:16:56 UTC 
Created attachment 118907 [details]
dmesg

-- system architecture: x86_64
-- kernel version: 4.3.0-rc5+ #12 SMP Thu Oct 15's drm-intel-nightly
-- Linux distribution: Fedora
-- Machine or mother board model: BDW
-- Display connector: eDP

-- Regression: Yes. Bisect points to 

bb1e52402b2a288b09ae37e8182599931c7e9df is the first bad commit
ommit bbb1e52402b2a288b09ae37e8182599931c7e9df
uthor: Rob Clark <robdclark@gmail.com>
ate:   Tue Aug 25 15:35:58 2015 -0400

   drm/fb-helper: atomic restore_fbdev_mode()..


-- Steps to reproduce:
1. Boot to X
2. Alternate first time to fbcon (Ctrl+Alt+F2)
3. Get back to X (Ctrl+Alt+F1)
4. Alternate second time to fbcon (Ctrl+Alt+F2)
...

Only the first time you go to fbcon you can actually get the console. After that you only get a blank screen.

-- Comments on dmesg:
My dmesg is full of custom printks..

at 30 sec it is the first time going to fbcon where everything works... On the second one at 53s it seems fb_helper->fb is corrupted.
Comment 1 Jani Nikula 2015-10-16 07:32:46 UTC 
*** Bug 92484 has been marked as a duplicate of this bug. ***
Comment 2 Rodrigo Vivi 2015-11-24 15:44:53 UTC 
Unfortunately I can't remember what the solution was, but it is fixed on recent kernel.
Comment 3 Rob Clark 2015-11-24 16:03:43 UTC 
(In reply to Rodrigo Vivi from comment #2)
> Unfortunately I can't remember what the solution was, but it is fixed on
> recent kernel.

fyi, 

commit a0fb6ad7ae28a4dce34c010028dc070eeacae1d9
Author:     Daniel Vetter <daniel.vetter@ffwll.ch>
AuthorDate: Fri Oct 16 19:11:30 2015 +0200

    drm/fb-helper: Fix fb refcounting in pan_display_atomic
Comment 4 Jari Tahvanainen 2017-01-10 12:21:38 UTC 
Closing resolved+fixed, fix is in upstream as said in comment 3.

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