[PATCH] amdgpu/pm/legacy: fix suspend/resume issues
Lazar, Lijo
lijo.lazar at amd.com
Mon Feb 17 10:00:55 UTC 2025
On 2/17/2025 3:26 PM, Lazar, Lijo wrote:
>
>
> On 2/12/2025 9:41 PM, Alex Deucher wrote:
>> From: "chr[]" <chris at rudorff.com>
>>
>> resume and irq handler happily races in set_power_state()
>>
>> * amdgpu_legacy_dpm_compute_clocks() needs lock
>> * protect irq work handler
>> * fix dpm_enabled usage
>>
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2524
>> Fixes: 3712e7a49459 ("drm/amd/pm: unified lock protections in amdgpu_dpm.c")
>> Signed-off-by: chr[] <chris at rudorff.com>
>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>> ---
>> drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c | 19 ++++++++++++++----
>> .../gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c | 2 ++
>> drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 20 +++++++++++++++----
>> 3 files changed, 33 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
>> index 67a8e22b1126d..db0d3d4dba685 100644
>> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
>> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c
>> @@ -3042,6 +3042,7 @@ static int kv_dpm_hw_init(struct amdgpu_ip_block *ip_block)
>> if (!amdgpu_dpm)
>> return 0;
>>
>> + mutex_lock(&adev->pm.mutex);
>> kv_dpm_setup_asic(adev);
>> ret = kv_dpm_enable(adev);
>> if (ret)
>> @@ -3049,6 +3050,8 @@ static int kv_dpm_hw_init(struct amdgpu_ip_block *ip_block)
>> else
>> adev->pm.dpm_enabled = true;
>> amdgpu_legacy_dpm_compute_clocks(adev);
>> + mutex_unlock(&adev->pm.mutex);
>> +
>> return ret;
>> }
>>
>> @@ -3067,10 +3070,13 @@ static int kv_dpm_suspend(struct amdgpu_ip_block *ip_block)
>> struct amdgpu_device *adev = ip_block->adev;
>>
>> if (adev->pm.dpm_enabled) {
>> + mutex_lock(&adev->pm.mutex);
>> + adev->pm.dpm_enabled = false;
>> /* disable dpm */
>> kv_dpm_disable(adev);
>> /* reset the power state */
>> adev->pm.dpm.current_ps = adev->pm.dpm.requested_ps = adev->pm.dpm.boot_ps;
>> + mutex_unlock(&adev->pm.mutex);
>> }
>> return 0;
>> }
>> @@ -3080,18 +3086,23 @@ static int kv_dpm_resume(struct amdgpu_ip_block *ip_block)
>> int ret;
>> struct amdgpu_device *adev = ip_block->adev;
>>
>> - if (adev->pm.dpm_enabled) {
>> + if (!amdgpu_dpm)
>> + return 0;
>> +
>> + if (!adev->pm.dpm_enabled) {
>> + mutex_lock(&adev->pm.mutex);
>> /* asic init will reset to the boot state */
>> kv_dpm_setup_asic(adev);
>> ret = kv_dpm_enable(adev);
>> if (ret)
>> adev->pm.dpm_enabled = false;
>
> Need braces here as well since else part is with braces.
>> - else
>> + else {
>> adev->pm.dpm_enabled = true;
>> - if (adev->pm.dpm_enabled)
>> amdgpu_legacy_dpm_compute_clocks(adev);
>> + }
>> + mutex_unlock(&adev->pm.mutex);
>> }
>> - return 0;
>> + return ret;
>
> Possibility of returning unintialized value.
>
>> }
>>
>> static bool kv_dpm_is_idle(void *handle)
>> 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 e861355ebd75b..e06c25c945007 100644
>> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
>> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
>> @@ -1012,6 +1012,7 @@ void amdgpu_dpm_thermal_work_handler(struct work_struct *work)
>> if (!adev->pm.dpm_enabled)
>> return;
>>
>> + mutex_lock(&adev->pm.mutex);
>
> I think taking this lock should happen before the dpm_enabled variable
> check. Otherwise, it could happen that part of this sequence might still
> go through after a kv/si_dpm_suspend.
One more comment - probably it's worthwhile to cancel any scheduled
amdgpu_dpm_thermal_work at the beginning of *_dpm_suspend.
Thanks,
Lijo
>
>> if (!pp_funcs->read_sensor(adev->powerplay.pp_handle,
>> AMDGPU_PP_SENSOR_GPU_TEMP,
>> (void *)&temp,
>> @@ -1033,4 +1034,5 @@ void amdgpu_dpm_thermal_work_handler(struct work_struct *work)
>> adev->pm.dpm.state = dpm_state;
>>
>> amdgpu_legacy_dpm_compute_clocks(adev->powerplay.pp_handle);
>> + mutex_unlock(&adev->pm.mutex);
>> }
>> 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 a87dcf0974bc1..c40ec4f74afb0 100644
>> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
>> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c
>> @@ -7786,6 +7786,7 @@ static int si_dpm_hw_init(struct amdgpu_ip_block *ip_block)
>> if (!amdgpu_dpm)
>> return 0;
>>
>> + mutex_lock(&adev->pm.mutex);
>> si_dpm_setup_asic(adev);
>> ret = si_dpm_enable(adev);
>> if (ret)
>> @@ -7793,6 +7794,7 @@ static int si_dpm_hw_init(struct amdgpu_ip_block *ip_block)
>> else
>> adev->pm.dpm_enabled = true;
>> amdgpu_legacy_dpm_compute_clocks(adev);
>> + mutex_unlock(&adev->pm.mutex);
>> return ret;
>> }
>>
>> @@ -7811,11 +7813,15 @@ static int si_dpm_suspend(struct amdgpu_ip_block *ip_block)
>> struct amdgpu_device *adev = ip_block->adev;
>>
>> if (adev->pm.dpm_enabled) {
>> + mutex_lock(&adev->pm.mutex);
>> + adev->pm.dpm_enabled = false;
>> /* disable dpm */
>> si_dpm_disable(adev);
>> /* reset the power state */
>> adev->pm.dpm.current_ps = adev->pm.dpm.requested_ps = adev->pm.dpm.boot_ps;
>> + mutex_unlock(&adev->pm.mutex);
>> }
>> +
>> return 0;
>> }
>>
>> @@ -7824,18 +7830,24 @@ static int si_dpm_resume(struct amdgpu_ip_block *ip_block)
>> int ret;
>> struct amdgpu_device *adev = ip_block->adev;
>>
>> - if (adev->pm.dpm_enabled) {
>> + if (!amdgpu_dpm)
>> + return 0;
>> +
>> + if (!adev->pm.dpm_enabled) {
>> /* asic init will reset to the boot state */
>> + mutex_lock(&adev->pm.mutex);
>> si_dpm_setup_asic(adev);
>> ret = si_dpm_enable(adev);
>> if (ret)
>> adev->pm.dpm_enabled = false;
>
> Same 'braces' comment.
>
>> - else
>> + else {
>> adev->pm.dpm_enabled = true;
>> - if (adev->pm.dpm_enabled)
>> amdgpu_legacy_dpm_compute_clocks(adev);
>> + }
>> + mutex_unlock(&adev->pm.mutex);
>> }
>> - return 0;
>> +
>> + return ret;
>
> Possibility of returning unintialized value.
>
> Thanks,
> Lijo
>
>> }
>>
>> static bool si_dpm_is_idle(void *handle)
>
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