Re: [PATCH] drm/i915: Replace sleep with GT idle wait

Andi Shyti <[email protected]> Thu, 30 Jul 2026 11:01:05 +0200
Newsgroups org.freedesktop.lists.intel-gfx,org.freedesktop.lists.dri-devel
Message-ID <[email protected]>
On Wed, Jul 22, 2026 at 09:22:28AM +0200, Andi Shyti wrote:
> On VT-d systems, the driver must ensure that the GT is idle
> before DMA object pages are unmapped.
> 
> Currently, the driver simply sleeps for 100-250 microseconds,
> which does not guarantee that all requests have completed and no
> further ones are being submitted. Replace the sleep with
> intel_gt_wait_for_idle() to explicitly wait until the GT has
> become idle.
> 
> An error is printed if waiting for the GT to become idle fails.
> 
> Signed-off-by: Andi Shyti <[email protected]>
> Cc: Chris Wilson <[email protected]>

NAK, this patch is doesn't fix anything and reintroduces the
livelock that Chris has tried to originally workaround.

Sorry for the noise.

Andi