Am 11.03.20 um 12:30 schrieb Zhu, James:
[AMD Official Use Only - Internal Distribution Only]
ping
------------------------------------------------------------------------
*From:* Zhu, James <james....@amd.com>
*Sent:* Monday, March 9, 2020 12:57 PM
*To:* amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org>
*Cc:* Zhu, James <james....@amd.com>; Koenig, Christian
<christian.koe...@amd.com>
*Subject:* [PATCH v3 1/4] drm/amdgpu/vcn: fix race condition issue for
vcn start
Fix race condition issue when multiple vcn starts are called.
v2: Removed checking the return value of cancel_delayed_work_sync()
to prevent possible races here.
v3: Add total_submission_cnt to avoid gate power unexpectedly.
Signed-off-by: James Zhu <james....@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 22 +++++++++++++++-------
drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h | 2 ++
2 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
index a41272f..6aafda1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
@@ -63,6 +63,8 @@ int amdgpu_vcn_sw_init(struct amdgpu_device *adev)
int i, r;
INIT_DELAYED_WORK(&adev->vcn.idle_work, amdgpu_vcn_idle_work_handler);
+ mutex_init(&adev->vcn.vcn_pg_lock);
+ atomic_set(&adev->vcn.total_submission_cnt, 0);
switch (adev->asic_type) {
case CHIP_RAVEN:
@@ -210,6 +212,7 @@ int amdgpu_vcn_sw_fini(struct amdgpu_device *adev)
}
release_firmware(adev->vcn.fw);
+ mutex_destroy(&adev->vcn.vcn_pg_lock);
return 0;
}
@@ -307,7 +310,8 @@ static void amdgpu_vcn_idle_work_handler(struct
work_struct *work)
fences += fence[j];
}
- if (fences == 0) {
+ if (fences == 0 &&
+ likely(atomic_read(&adev->vcn.total_submission_cnt) == 0)) {
amdgpu_gfx_off_ctrl(adev, true);
amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,
AMD_PG_STATE_GATE);
@@ -319,13 +323,14 @@ static void amdgpu_vcn_idle_work_handler(struct
work_struct *work)
void amdgpu_vcn_ring_begin_use(struct amdgpu_ring *ring)
{
struct amdgpu_device *adev = ring->adev;
- bool set_clocks = !cancel_delayed_work_sync(&adev->vcn.idle_work);
- if (set_clocks) {
- amdgpu_gfx_off_ctrl(adev, false);
- amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,
- AMD_PG_STATE_UNGATE);
- }
+ atomic_inc(&adev->vcn.total_submission_cnt);
+ cancel_delayed_work_sync(&adev->vcn.idle_work);
+
+ mutex_lock(&adev->vcn.vcn_pg_lock);
+ amdgpu_gfx_off_ctrl(adev, false);
+ amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_VCN,
+ AMD_PG_STATE_UNGATE);
if (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG) {
struct dpg_pause_state new_state;
@@ -345,11 +350,14 @@ void amdgpu_vcn_ring_begin_use(struct
amdgpu_ring *ring)
adev->vcn.pause_dpg_mode(adev, ring->me, &new_state);
}
+ mutex_unlock(&adev->vcn.vcn_pg_lock);
}
void amdgpu_vcn_ring_end_use(struct amdgpu_ring *ring)
{
schedule_delayed_work(&ring->adev->vcn.idle_work, VCN_IDLE_TIMEOUT);
+ if
(unlikely(atomic_dec_return(&ring->adev->vcn.total_submission_cnt) < 0))
+ atomic_set(&ring->adev->vcn.total_submission_cnt, 0);
You need to decrement first and then call schedule_delayed_work()
otherwise the work could run with the wrong counter.
And the extra check for an under run should be superfluous.
Regards,
Christian.
}
int amdgpu_vcn_dec_ring_test_ring(struct amdgpu_ring *ring)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
index 6fe0573..111c4cc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
@@ -200,6 +200,8 @@ struct amdgpu_vcn {
struct drm_gpu_scheduler
*vcn_dec_sched[AMDGPU_MAX_VCN_INSTANCES];
uint32_t num_vcn_enc_sched;
uint32_t num_vcn_dec_sched;
+ struct mutex vcn_pg_lock;
+ atomic_t total_submission_cnt;
unsigned harvest_config;
int (*pause_dpg_mode)(struct amdgpu_device *adev,
--
2.7.4
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
