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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-04 15:32:37 (GMT) |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-04 19:20:03 (GMT) |
| commit | faf5bf0ad62b332769199cc09c678287ab3c5f08 (patch) | |
| tree | 3241133ceb805b7fec3071e886c661c5cfe4944c /drivers/gpu/drm/i915/i915_debugfs.c | |
| parent | b5add9591ca5b869b8c9c559e16ccab8a8ba4727 (diff) | |
| download | linux-faf5bf0ad62b332769199cc09c678287ab3c5f08.tar.xz | |
drm/i915: Use atomics to manipulate obj->frontbuffer_bits
The individual bits inside obj->frontbuffer_bits are protected by each
plane->mutex, but the whole bitfield may be accessed by multiple KMS
operations simultaneously and so the RMW need to be under atomics.
However, for updating the single field we do not need to mandate that it
be under the struct_mutex, one more step towards its removal as the de
facto BKL.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470324762-2545-21-git-send-email-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_debugfs.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_debugfs.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 8d47d1bf..9796b07 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -138,6 +138,7 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) struct drm_i915_private *dev_priv = to_i915(obj->base.dev); struct intel_engine_cs *engine; struct i915_vma *vma; + unsigned int frontbuffer_bits; int pin_count = 0; enum intel_engine_id id; @@ -204,8 +205,9 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) if (engine) seq_printf(m, " (%s)", engine->name); - if (obj->frontbuffer_bits) - seq_printf(m, " (frontbuffer: 0x%03x)", obj->frontbuffer_bits); + frontbuffer_bits = atomic_read(&obj->frontbuffer_bits); + if (frontbuffer_bits) + seq_printf(m, " (frontbuffer: 0x%03x)", frontbuffer_bits); } static int i915_gem_object_list_info(struct seq_file *m, void *data) |