[PATCH V2] drm/amd/pm: fix the deadlock issue observed on SI
Evan Quan
evan.quan at amd.com
Mon Apr 11 08:54:53 UTC 2022
The adev->pm.mutx is already held at the beginning of
amdgpu_dpm_compute_clocks/amdgpu_dpm_enable_uvd/amdgpu_dpm_enable_vce.
But on their calling path, amdgpu_display_bandwidth_update will be
called and thus its sub functions amdgpu_dpm_get_sclk/mclk. They
will then try to acquire the same adev->pm.mutex and deadlock will
occur.
By placing amdgpu_display_bandwidth_update outside of adev->pm.mutex
protection(considering logically they do not need such protection) and
restructuring the call flow accordingly, we can eliminate the deadlock
issue. This comes with no real logics change.
Fixes: 3712e7a49459 ("drm/amd/pm: unified lock protections in amdgpu_dpm.c")
Reported-by: Paul Menzel <pmenzel at molgen.mpg.de>
Reported-by: Arthur Marsh <arthur.marsh at internode.on.net>
Link: https: //lore.kernel.org/all/9e689fea-6c69-f4b0-8dee-32c4cf7d8f9c at molgen.mpg.de/
BugLink: https: //gitlab.freedesktop.org/drm/amd/-/issues/1957
Signed-off-by: Evan Quan <evan.quan at amd.com>
--
v1->v2:
- rich the commit messages(Paul)
---
drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 39 +++++++++++++++++++
.../gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c | 10 -----
drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 35 -----------------
.../gpu/drm/amd/pm/powerplay/amd_powerplay.c | 10 -----
4 files changed, 39 insertions(+), 55 deletions(-)
diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
index 5504d81c77b7..72e7b5d40af6 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
@@ -427,6 +427,7 @@ int amdgpu_dpm_read_sensor(struct amdgpu_device *adev, enum amd_pp_sensors senso
void amdgpu_dpm_compute_clocks(struct amdgpu_device *adev)
{
const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+ int i;
if (!adev->pm.dpm_enabled)
return;
@@ -434,6 +435,15 @@ void amdgpu_dpm_compute_clocks(struct amdgpu_device *adev)
if (!pp_funcs->pm_compute_clocks)
return;
+ if (adev->mode_info.num_crtc)
+ amdgpu_display_bandwidth_update(adev);
+
+ for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
+ struct amdgpu_ring *ring = adev->rings[i];
+ if (ring && ring->sched.ready)
+ amdgpu_fence_wait_empty(ring);
+ }
+
mutex_lock(&adev->pm.mutex);
pp_funcs->pm_compute_clocks(adev->powerplay.pp_handle);
mutex_unlock(&adev->pm.mutex);
@@ -443,6 +453,20 @@ void amdgpu_dpm_enable_uvd(struct amdgpu_device *adev, bool enable)
{
int ret = 0;
+ if (adev->family == AMDGPU_FAMILY_SI) {
+ mutex_lock(&adev->pm.mutex);
+ if (enable) {
+ adev->pm.dpm.uvd_active = true;
+ adev->pm.dpm.state = POWER_STATE_TYPE_INTERNAL_UVD;
+ } else {
+ adev->pm.dpm.uvd_active = false;
+ }
+ mutex_unlock(&adev->pm.mutex);
+
+ amdgpu_dpm_compute_clocks(adev);
+ return;
+ }
+
ret = amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_UVD, !enable);
if (ret)
DRM_ERROR("Dpm %s uvd failed, ret = %d. \n",
@@ -453,6 +477,21 @@ void amdgpu_dpm_enable_vce(struct amdgpu_device *adev, bool enable)
{
int ret = 0;
+ if (adev->family == AMDGPU_FAMILY_SI) {
+ mutex_lock(&adev->pm.mutex);
+ if (enable) {
+ adev->pm.dpm.vce_active = true;
+ /* XXX select vce level based on ring/task */
+ adev->pm.dpm.vce_level = AMD_VCE_LEVEL_AC_ALL;
+ } else {
+ adev->pm.dpm.vce_active = false;
+ }
+ mutex_unlock(&adev->pm.mutex);
+
+ amdgpu_dpm_compute_clocks(adev);
+ return;
+ }
+
ret = amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_VCE, !enable);
if (ret)
DRM_ERROR("Dpm %s vce failed, ret = %d. \n",
diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
index 9613c6181c17..d3fe149d8476 100644
--- a/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
+++ b/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
@@ -1028,16 +1028,6 @@ static int amdgpu_dpm_change_power_state_locked(struct amdgpu_device *adev)
void amdgpu_legacy_dpm_compute_clocks(void *handle)
{
struct amdgpu_device *adev = (struct amdgpu_device *)handle;
- int i = 0;
-
- if (adev->mode_info.num_crtc)
- amdgpu_display_bandwidth_update(adev);
-
- for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
- struct amdgpu_ring *ring = adev->rings[i];
- if (ring && ring->sched.ready)
- amdgpu_fence_wait_empty(ring);
- }
amdgpu_dpm_get_active_displays(adev);
diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
index caae54487f9c..633dab14f51c 100644
--- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
+++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
@@ -3892,40 +3892,6 @@ static int si_set_boot_state(struct amdgpu_device *adev)
}
#endif
-static int si_set_powergating_by_smu(void *handle,
- uint32_t block_type,
- bool gate)
-{
- struct amdgpu_device *adev = (struct amdgpu_device *)handle;
-
- switch (block_type) {
- case AMD_IP_BLOCK_TYPE_UVD:
- if (!gate) {
- adev->pm.dpm.uvd_active = true;
- adev->pm.dpm.state = POWER_STATE_TYPE_INTERNAL_UVD;
- } else {
- adev->pm.dpm.uvd_active = false;
- }
-
- amdgpu_legacy_dpm_compute_clocks(handle);
- break;
- case AMD_IP_BLOCK_TYPE_VCE:
- if (!gate) {
- adev->pm.dpm.vce_active = true;
- /* XXX select vce level based on ring/task */
- adev->pm.dpm.vce_level = AMD_VCE_LEVEL_AC_ALL;
- } else {
- adev->pm.dpm.vce_active = false;
- }
-
- amdgpu_legacy_dpm_compute_clocks(handle);
- break;
- default:
- break;
- }
- return 0;
-}
-
static int si_set_sw_state(struct amdgpu_device *adev)
{
return (amdgpu_si_send_msg_to_smc(adev, PPSMC_MSG_SwitchToSwState) == PPSMC_Result_OK) ?
@@ -8125,7 +8091,6 @@ static const struct amd_pm_funcs si_dpm_funcs = {
.print_power_state = &si_dpm_print_power_state,
.debugfs_print_current_performance_level = &si_dpm_debugfs_print_current_performance_level,
.force_performance_level = &si_dpm_force_performance_level,
- .set_powergating_by_smu = &si_set_powergating_by_smu,
.vblank_too_short = &si_dpm_vblank_too_short,
.set_fan_control_mode = &si_dpm_set_fan_control_mode,
.get_fan_control_mode = &si_dpm_get_fan_control_mode,
diff --git a/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c
index dbed72c1e0c6..1eb4e613b27a 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c
@@ -1503,16 +1503,6 @@ static void pp_pm_compute_clocks(void *handle)
{
struct pp_hwmgr *hwmgr = handle;
struct amdgpu_device *adev = hwmgr->adev;
- int i = 0;
-
- if (adev->mode_info.num_crtc)
- amdgpu_display_bandwidth_update(adev);
-
- for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
- struct amdgpu_ring *ring = adev->rings[i];
- if (ring && ring->sched.ready)
- amdgpu_fence_wait_empty(ring);
- }
if (!amdgpu_device_has_dc_support(adev)) {
amdgpu_dpm_get_active_displays(adev);
--
2.29.0
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