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authorDave Airlie <airlied@redhat.com>2014-11-11 09:16:15 +1000
committerAlex Deucher <alexander.deucher@amd.com>2014-11-11 17:22:26 -0500
commit1c9498425453bb65ef339a57705c5ef59fe1541d (patch)
tree293c1d2d23aa2269a67d13d8a5486cc3c6ccf549 /drivers/gpu/drm/radeon/atombios_dp.c
parent03dca708521d30153fc5c7e2ff136f780a7372c9 (diff)
downloadblackbird-op-linux-1c9498425453bb65ef339a57705c5ef59fe1541d.tar.gz
blackbird-op-linux-1c9498425453bb65ef339a57705c5ef59fe1541d.zip
drm/radeon: add locking around atombios scratch space usage
While developing MST support I noticed I often got the wrong data back from a transaction, in a racy fashion. I noticed the scratch space wasn't locked against concurrent users. Based on a patch by Alex, but I've made it a bit more obvious when things are locked. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/gpu/drm/radeon/atombios_dp.c')
-rw-r--r--drivers/gpu/drm/radeon/atombios_dp.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 95d5d4ab3335..11ba9d21b89b 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -100,6 +100,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex);
+ mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
@@ -113,7 +114,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
if (ASIC_IS_DCE4(rdev))
args.v2.ucHPD_ID = chan->rec.hpd;
- atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+ atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
*ack = args.v1.ucReplyStatus;
@@ -147,6 +148,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
r = recv_bytes;
done:
+ mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
mutex_unlock(&chan->mutex);
return r;
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