Bug 205523

Summary: AMDGPU display lockup during boot with 5.4 RC on Ryzen 2700u
Product: Drivers Reporter: briancschott
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: NEW ---    
Severity: normal CC: alexdeucher, bjo, harry.wentland, haxk612, postix
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 5.4.0-rc7 Subsystem:
Regression: No Bisected commit-id:
Attachments: journalctl output

Description briancschott 2019-11-14 07:03:28 UTC
Created attachment 285907 [details]
journalctl output

I'm getting a black screen on boot when testing the 5.4 release candidate kernels on a Dell Inspiron 7375 laptop. The system responds to the magic sysrq, so the kernel is not completely dead, but the display is. The system boots correctly with a 5.3.1 kernel. The log showing the stack trace is attached. I'll start working on bisecting the problem soon.
Comment 1 briancschott 2019-11-14 11:19:25 UTC
1c4259159132ae4ceaf7c6db37a6cf76417f73d9 is the first bad commit
commit 1c4259159132ae4ceaf7c6db37a6cf76417f73d9
Author: Shirish S <shirish.s@amd.com>
Date:   Tue Jul 16 14:49:48 2019 +0530

    drm/amd/display: enable S/G for RAVEN chip
    
    enables gpu_vm_support in dm and adds
    AMDGPU_GEM_DOMAIN_GTT as supported domain
    
    v2:
    Move BO placement logic into amdgpu_display_supported_domains
    
    v3:
    Use amdgpu_bo_validate_uswc in amdgpu_display_supported_domains.
    
    v4:
    amdgpu_bo_validate_uswc moved to sepperate patch.
    
    Signed-off-by: Shirish S <shirish.s@amd.com>
    Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
    Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c       | 2 +-
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
Comment 2 Alex Deucher 2019-11-14 15:04:49 UTC
Does disabling the IOMMU help?  Set iommu=off or iommu=pt on the kernel command line.
Comment 3 briancschott 2019-11-14 20:14:53 UTC
"iommu=off" seems to work, "iommu=pt" does not.
Comment 4 Haxk20 2019-11-23 18:39:46 UTC
(In reply to Alex Deucher from comment #2)
> Does disabling the IOMMU help?  Set iommu=off or iommu=pt on the kernel
> command line.

Is this permanent too ? This will regress and produce tearing in games running with PRIME setup.