Sorry, I just saw your discussion with Evan. Checking the conditions in
the worker function should work. Feel free to add my Reviewed-by.
Regards,
 Felix
On 2018-07-30 03:33 PM, Felix Kuehling wrote:
> NACK.
>
> See inline ...
>
>
> On 2018-07-30 05:23 AM, Rex Zhu wrote:
>> delay to enable gfx off feature to avoid gfx on/off frequently
>> suggested by Alex and Evan.
>>
>> Signed-off-by: Rex Zhu <Rex.Zhu at amd.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 15 +++++++++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 8 ++++++--
>> 3 files changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> index 188bc53..ff16689 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> @@ -992,6 +992,8 @@ struct amdgpu_gfx {
>> bool gfx_off_state; /* true: enabled, false: disabled */
>> struct mutex gfx_off_mutex;
>> uint32_t gfx_off_req_count; /* default 1, enable gfx off: dec 1, disable gfx off: add 1 */
>> + struct delayed_work gfx_off_delay_work;
>> +
>> /* pipe reservation */
>> struct mutex pipe_reserve_mutex;
>> DECLARE_BITMAP (pipe_reserve_bitmap, AMDGPU_MAX_COMPUTE_QUEUES);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 122653f..f6a6fb5 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -1925,6 +1925,19 @@ static void amdgpu_device_ip_late_init_func_handler(struct work_struct *work)
>> DRM_ERROR("ib ring test failed (%d).\n", r);
>> }
>>
>> +static void amdgpu_device_delay_enable_gfx_off(struct work_struct *work)
>> +{
>> + struct amdgpu_device *adev =
>> + container_of(work, struct amdgpu_device, gfx.gfx_off_delay_work.work);
>> +
>> + mutex_lock(&adev->gfx.gfx_off_mutex);
>> + if (!adev->gfx.gfx_off_state && !adev->gfx.gfx_off_req_count) {
>> + if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, true))
>> + adev->gfx.gfx_off_state = true;
>> + }
>> + mutex_unlock(&adev->gfx.gfx_off_mutex);
>> +}
>> +
>> /**
>> * amdgpu_device_ip_suspend_phase1 - run suspend for hardware IPs (phase 1)
>> *
>> @@ -2394,6 +2407,8 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>>
>> INIT_DELAYED_WORK(&adev->late_init_work,
>> amdgpu_device_ip_late_init_func_handler);
>> + INIT_DELAYED_WORK(&adev->gfx.gfx_off_delay_work,
>> + amdgpu_device_delay_enable_gfx_off);
>>
>> adev->gfx.gfx_off_req_count = 1;
>> adev->pm.ac_power = power_supply_is_system_supplied() > 0 ? true : false;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
>> index 1cdb264..11d4d9f 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
>> @@ -26,6 +26,9 @@
>> #include "amdgpu.h"
>> #include "amdgpu_gfx.h"
>>
>> +/* 0.5 second timeout */
>> +#define GFX_OFF_DELAY_ENABLE msecs_to_jiffies(500)
>> +
>> /*
>> * GPU scratch registers helpers function.
>> */
>> @@ -360,6 +363,7 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable)
>> if (!adev->powerplay.pp_funcs->set_powergating_by_smu)
>> return;
>>
>> +
>> mutex_lock(&adev->gfx.gfx_off_mutex);
>>
>> if (!enable)
>> @@ -368,11 +372,11 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable)
>> adev->gfx.gfx_off_req_count--;
>>
>> if (enable && !adev->gfx.gfx_off_state && !adev->gfx.gfx_off_req_count) {
>> - if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, true))
>> - adev->gfx.gfx_off_state = true;
>> + schedule_delayed_work(&adev->gfx.gfx_off_delay_work, GFX_OFF_DELAY_ENABLE);
>> } else if (!enable && adev->gfx.gfx_off_state) {
> There may still be delayed work pending to enable GFXOFF. You need to
> use cancel_delayed_work_sync to cancel it and make sure GFXOFF doesn't
> get enabled again while your caller still needs it disabled.
>
> That may also wait for a worker function that has already started.
> Therefore you need to cancel before taking the gfx_off_mutex, otherwise
> you can deadlock with the worker function trying to take the lock as well.
>
> Regards,
> Â Felix
>
>> if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, false))
>> adev->gfx.gfx_off_state = false;
>> }
>> +
>> mutex_unlock(&adev->gfx.gfx_off_mutex);
>> }
> _______________________________________________
> amd-gfx mailing list
> amd-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
