[PATCH v2] drm/amdgpu:No action when VCN PG state is unchanged
James Zhu
jamesz at amd.com
Thu Sep 20 16:24:44 UTC 2018
On 2018-09-20 11:49 AM, Alex Deucher wrote:
> On Thu, Sep 20, 2018 at 11:27 AM James Zhu <jamesz at amd.com> wrote:
>>
>>
>> On 2018-09-20 11:14 AM, Alex Deucher wrote:
>>> On Thu, Sep 13, 2018 at 4:56 PM James Zhu <jzhums at gmail.com> wrote:
>>>> When VCN PG state is unchanged, it is unnecessary to reset power
>>>> gate state
>>>>
>>>> Signed-off-by: James Zhu <James.Zhu at amd.com>
>>>> ---
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h | 1 +
>>>> drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c | 12 ++++++++++--
>>>> 2 files changed, 11 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
>>>> index 0b0b863..d2219ab 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h
>>>> @@ -69,6 +69,7 @@ struct amdgpu_vcn {
>>>> struct amdgpu_ring ring_jpeg;
>>>> struct amdgpu_irq_src irq;
>>>> unsigned num_enc_rings;
>>>> + enum amd_powergating_state cur_state;
>>> Does the default value (0) at init time properly reflect the default
>>> powergating state? If so,
>>> Acked-by: Alex Deucher <alexander.deucher at amd.com>
>> Yes, the below code shows it will be set to 0 during driver load stage.
> Yes, I understand that. Is 0 (AMD_PG_STATE_GATE) what we want as the
> default though? The first time the code runs are we going to do the
> right thing or is the code going to return early? IIRC, the hw
> default is ungated.
cur_state is used for tracking driver SW PG state, not HW PG state.
I though no matter what HW PG state is after device powers up, when
first vcn ring is scheduled to run,
begin_use->set_powergating_state->vcn_v1_0_start->ungate
power/clock->Boot_VCPU will be tried.
For DPG mode, the ungate power/clock , boot VCPU will not actually be
activated during start setup stage, and
only be activated during ring run stage.
James
> Alex
>> int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
>> ....
>> adev = kzalloc(sizeof(struct amdgpu_device), GFP_KERNEL);
>>
>> struct amdgpu_device {
>> ....
>> struct amdgpu_vcn vcn;
>>
>> Best Regards!
>> James zhu
>>>> };
>>>>
>>>> int amdgpu_vcn_sw_init(struct amdgpu_device *adev);
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c b/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
>>>> index 2664bb2..2cde0b4 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
>>>> @@ -1633,12 +1633,20 @@ static int vcn_v1_0_set_powergating_state(void *handle,
>>>> * revisit this when there is a cleaner line between
>>>> * the smc and the hw blocks
>>>> */
>>>> + int ret;
>>>> struct amdgpu_device *adev = (struct amdgpu_device *)handle;
>>>>
>>>> + if(state == adev->vcn.cur_state)
>>>> + return 0;
>>>> +
>>>> if (state == AMD_PG_STATE_GATE)
>>>> - return vcn_v1_0_stop(adev);
>>>> + ret = vcn_v1_0_stop(adev);
>>>> else
>>>> - return vcn_v1_0_start(adev);
>>>> + ret = vcn_v1_0_start(adev);
>>>> +
>>>> + if(!ret)
>>>> + adev->vcn.cur_state = state;
>>>> + return ret;
>>>> }
>>>>
>>>> static const struct amd_ip_funcs vcn_v1_0_ip_funcs = {
>>>> --
>>>> 2.7.4
>>>>
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>>>> amd-gfx at lists.freedesktop.org
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