Delayed freeze with DRI_PRIME=1 on Topaz

Submitted by SET

Assigned to Default DRI bug account

Link to original bug (#107950)

Description

Host : laptop with Kaveri iGPU and Topaz dGPU
kernel : 4.18.4
Xorg : 1.20.1
Mesa : 18.2.0


When running 'DRI_PRIME=1 glmark2', the systems hangs after about 60 seconds. Must reboot wildly with the power button or magic sysrq, the latter may not completely power off the laptop.

The iGPU is driven by radeon module, and the dGPU with amdgpu. No module options, or the following options (amdgpu cik_support=0 si_support=1; radeon cik_support=1 si_support=0) yield the same result.

I can't say it started with 4.18.4. It's observed on 4.19-rc2/3 also. This never happened with older kernels.

No such event occurs when using the iGPU.

I cannot bisect, because the last crash badly corrupted the home partition, and my home directory simply vanished after fsck recreated the ext4 journal. I could recover from backup fortunately.

May be it's not related to amdgpu, but rather to Xorg, mesa or anything else. I am reporting it here in case it could be amdgpu in such offloading context.

Regards.