Bug 217945 - DRM error - flickering screen with mouse cursor over low right corner - with IOMMU
Summary: DRM error - flickering screen with mouse cursor over low right corner - with...
Status: RESOLVED ANSWERED
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(Other) (show other bugs)
Hardware: Intel Linux
: P3 high
Assignee: drivers_video-other
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2023-09-24 18:08 UTC by jb
Modified: 2023-09-25 09:26 UTC (History)
1 user (show)

See Also:
Kernel Version:
Subsystem:
Regression: No
Bisected commit-id:

Attachments
iommu-on-bad-dell.txt log (6.59 KB, text/plain)
2023-09-24 18:08 UTC, jb 		Details
iommu-off-good-dell.txt log (3.48 KB, text/plain)
2023-09-24 18:14 UTC, jb 		Details
lspci-dell.txt output (10.98 KB, text/plain)
2023-09-24 18:15 UTC, jb 		Details
kernel-config-dell.txt output (260.15 KB, text/plain)
2023-09-24 18:16 UTC, jb 		Details
iommu-on-vga-chip-off-good-lenovo.txt log (6.12 KB, text/plain)
2023-09-24 18:17 UTC, jb 		Details
Add an attachment (proposed patch, testcase, etc.)

Description jb 2023-09-24 18:08:49 UTC 
Created attachment 305141 [details]
iommu-on-bad-dell.txt log

I have a Dell Latitude 5500 laptop that has a flickering screen problem (with DRM error in logs) when I enable IOMMU (on kernel boot command line as most distros disable it per kernel config).
I tested it with latest kernel 6.5.4 .
Please find attachments with related entries:
iommu-off-good-dell.txt  iommu-on-bad-dell.txt  kernel-config-dell.txt  lspci-dell.txt

In addition, for comparison (it may help in debugging), I also included an output from a Lenovo e550 laptop, which has the same OS (Arch Linux) and kernel and its config, with IOMMU enabled as above, but without the problem.
Please find attachment swith related entries:
ommu-on-vga-chip-off-good-lenovo.txt
NOTE: the log shows an interesting line:
pci 0000:00:02.0: DMAR: Disabling IOMMU for graphics on this chipset

Both laptops have Intel VT-x amd VT-d enabled in EFI (Dell) and BIOS (Lenovo).
I also tested the Dell laptop with latest Manjaro live and Win 10, and there is no problem (hardware, etc).
Comment 1 jb 2023-09-24 18:14:12 UTC 
Created attachment 305142 [details]
iommu-off-good-dell.txt log
Comment 2 jb 2023-09-24 18:15:11 UTC 
Created attachment 305143 [details]
lspci-dell.txt output
Comment 3 jb 2023-09-24 18:16:04 UTC 
Created attachment 305144 [details]
kernel-config-dell.txt output
Comment 4 jb 2023-09-24 18:17:35 UTC 
Created attachment 305145 [details]
iommu-on-vga-chip-off-good-lenovo.txt log
Comment 5 Bagas Sanjaya 2023-09-25 07:17:22 UTC 
(In reply to jb from comment #0)
> Both laptops have Intel VT-x amd VT-d enabled in EFI (Dell) and BIOS
> (Lenovo).
> I also tested the Dell laptop with latest Manjaro live and Win 10, and there
> is no problem (hardware, etc).

What kernel version on that Manjaro ISO?
Comment 6 jb 2023-09-25 08:52:09 UTC 
(In reply to Bagas Sanjaya from comment #5)
> (In reply to jb from comment #0)
> > Both laptops have Intel VT-x amd VT-d enabled in EFI (Dell) and BIOS
> > (Lenovo).
> > I also tested the Dell laptop with latest Manjaro live and Win 10, and
> there
> > is no problem (hardware, etc).
> 
> What kernel version on that Manjaro ISO?

Manjaro 23.0.1 iso, default kernel 6.5.1-1, with IOMMU disabled as usual.
Comment 7 Artem S. Tashkinov 2023-09-25 09:26:29 UTC 
Please post here as well:

https://gitlab.freedesktop.org/drm/intel/-/issues

No need to upload files twice, you can simply link to this issue.
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