nouveau: fix disabling the nonstall irq due to storm code

[ Upstream commit 0ef5c4e4 ]

Nouveau has code that when it gets an IRQ with no allowed handler
it disables it to avoid storms.

However with nonstall interrupts, we often disable them from
the drm driver, but still request their emission via the push submission.

Just don't disable nonstall irqs ever in normal operation, the
event handling code will filter them out, and the driver will
just enable/disable them at load time.

This fixes timeouts we've been seeing on/off for a long time,
but they became a lot more noticeable on Blackwell.

This doesn't fix all of them, there is a subsequent fence emission
fix to fix the last few.

Fixes: 3ebd64aa ("drm/nouveau/intr: support multiple trees, and explicit interfaces")
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://lore.kernel.org/r/20250829021633.1674524-1-airlied@gmail.com


[ Fix a typo and a minor checkpatch.pl warning; remove "v2" from commit
  subject. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
[ Apply to drivers/gpu/drm/nouveau/nvkm/engine/fifo/r535.c ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>