diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-10-15 13:21:35 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-10-15 15:38:19 +0100 |
| commit | d46b60a2e8d246f1f0faa38e52f4f5a73858c338 (patch) | |
| tree | a5b73c3b14544544dbb6aea89dd257a93d5697ea | |
| parent | 4d8a5cfe3b131f60903949f998c5961cc922e0b0 (diff) | |
drm/i915: Mark ininitial fb obj as WT on eLLC machines to avoid rcu lockup during fbdev init
Currently we leave the cache_level of the initial fb obj
set to NONE. This means on eLLC machines the first pin_to_display()
will try to switch it to WT which requires a vma unbind+bind.
If that happens during the fbdev initialization rcu does not
seem operational which causes the unbind to get stuck. To
most appearances this looks like a dead machine on boot.
Avoid the unbind by already marking the object cache_level
as WT when creating it. We still do an excplicit ggtt pin
which will rewrite the PTEs anyway, so they will match whatever
cache level we set.
Cc: <stable@vger.kernel.org> # v5.7+
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2381
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007120329.17076-1-ville.syrjala@linux.intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20201015122138.30161-1-chris@chris-wilson.co.uk
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_display.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index c8b1dd1a9e46..4d58a4710f2a 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -3433,6 +3433,14 @@ initial_plane_vma(struct drm_i915_private *i915, if (IS_ERR(obj)) return NULL; + /* + * Mark it WT ahead of time to avoid changing the + * cache_level during fbdev initialization. The + * unbind there would get stuck waiting for rcu. + */ + i915_gem_object_set_cache_coherency(obj, HAS_WT(i915) ? + I915_CACHE_WT : I915_CACHE_NONE); + switch (plane_config->tiling) { case I915_TILING_NONE: break; |