FAILED: patch "[PATCH] drm/i915/gem: Flush contexts on driver release" failed to apply to 6.0-stable tree

FAILED: patch "[PATCH] drm/i915/gem: Flush contexts on driver release" failed to apply to 6.0-stable tree

[gregkh]

The patch below does not apply to the 6.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

Possible dependencies:

1cec34442408 ("drm/i915/gem: Flush contexts on driver release")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1cec34442408a77ba5396b19725fed2c398005c3 Mon Sep 17 00:00:00 2001
From: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Date: Fri, 16 Sep 2022 11:24:02 +0200
Subject: [PATCH] drm/i915/gem: Flush contexts on driver release

Due to i915_perf assuming that it can use the i915_gem_context reference
to protect its i915->gem.contexts.list iteration, we need to defer removal
of the context from the list until last reference to the context is put.
However, there is a risk of triggering kernel warning on contexts list not
empty at driver release time if we deleagate that task to a worker for
i915_gem_context_release_work(), unless that work is flushed first.
Unfortunately, it is not flushed on driver release.  Fix it.

Instead of additionally calling flush_workqueue(), either directly or via
a new dedicated wrapper around it, replace last call to
i915_gem_drain_freed_objects() with existing i915_gem_drain_workqueue()
that performs both tasks.

Fixes: 75eefd82581f ("drm/i915: Release i915_gem_context from a worker")
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: stable@kernel.org # v5.16+
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220916092403.201355-2-janusz.krzysztofik@linux.intel.com

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index be7fede6cd6f..4539431a3c3e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1214,7 +1214,8 @@ void i915_gem_driver_release(struct drm_i915_private *dev_priv)
 		intel_uc_cleanup_firmwares(&gt->uc);
 	}
 
-	i915_gem_drain_freed_objects(dev_priv);
+	/* Flush any outstanding work, including i915_gem_context.release_work. */
+	i915_gem_drain_workqueue(dev_priv);
 
 	drm_WARN_ON(&dev_priv->drm, !list_empty(&dev_priv->gem.contexts.list));
 }