Re: [BUG][v6.9-rc6] Deadlock with: Revert "drm/qxl: simplify qxl_fence_wait"

From: Anders Blomdell
Date: Wed May 08 2024 - 08:42:51 EST




On 2024-05-07 11:03, Steven Rostedt wrote:
On Tue, 7 May 2024 15:54:21 +1000
David Airlie <airlied@xxxxxxxxxx> wrote:

I expec this will reintroduce the other problems that caused this
change in the first place, but I think this should at least bring us
back to regression equilibrium. I can't recommend anyone use qxl hw
over virtio-gpu hw in their VMs, since virtio-gpu is actually hw
designed for virt.

I agree that it will likely cause the issues that this was addressing
to come back, but you can't have a fix that introduces a deadlock.

Perhaps the deadlock didn't exist before, and the printk updates
changed the way it works to introduce it now?
It deadlocks on 6.8.8 under qemu/kvm, reverting the patch fixes the problem there as well (6.8.7 hangs as well, but I have not tested reverting on that version)

/Anders