diff options
| author | Jerry Zuo <Jerry.Zuo@amd.com> | 2017-07-31 17:10:44 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2017-09-26 18:16:36 -0400 |
| commit | e8cd26434df0cd8d97f31aeb4399afcdc37fcfda (patch) | |
| tree | 26614c3e36f8cb14e10d34a5431c4dcf2efe820f /drivers/gpu/drm/amd/display/dc/core/dc_sink.c | |
| parent | f81483c4ccca0d2ceca14ee15564a14f2c34eb2c (diff) | |
drm/amd/display: Use atomic types for ref_count
Current ref_count inc/dec is not guarded by locks which leads to
a raced condition where two threads try to access the variable
at the same time. In this case, both might act on the same cached
value and inc/dec from the same value, rather than inc/dec by 2.
Signed-off-by: Jerry Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/core/dc_sink.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_sink.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_sink.c b/drivers/gpu/drm/amd/display/dc/core/dc_sink.c index a83f1243a9d1..7717350297a5 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_sink.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_sink.c @@ -63,16 +63,16 @@ static bool construct(struct dc_sink *sink, const struct dc_sink_init_data *init void dc_sink_retain(struct dc_sink *sink) { - ASSERT(sink->ref_count > 0); - ++sink->ref_count; + ASSERT(atomic_read(&sink->ref_count) > 0); + atomic_inc(&sink->ref_count); } void dc_sink_release(struct dc_sink *sink) { - ASSERT(sink->ref_count > 0); - --sink->ref_count; + ASSERT(atomic_read(&sink->ref_count) > 0); + atomic_dec(&sink->ref_count); - if (sink->ref_count == 0) { + if (atomic_read(&sink->ref_count) == 0) { destruct(sink); dm_free(sink); } @@ -88,7 +88,7 @@ struct dc_sink *dc_sink_create(const struct dc_sink_init_data *init_params) if (false == construct(sink, init_params)) goto construct_fail; - ++sink->ref_count; + atomic_inc(&sink->ref_count); return sink; |