diff mbox series

[5/6] drm/msm/a6xx: Use GMU_ALWAYS_ON_COUNTER for GMU-equipped GPUs in timestamp

Message ID 20230517-topic-a7xx_prep-v1-5-7a964f2e99c2@linaro.org
State New
Headers
Series Adreno QoL changes |

Commit Message

Konrad Dybcio May 17, 2023, 4:50 p.m. UTC 
  Use the always-on counter provided by the GMU to skip having to
keep the GPU online.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Comments

Jonathan Marek May 17, 2023, 6:09 p.m. UTC | #1 
AFAIK GMU_ALWAYS_ON_COUNTER does not have the same value as 
CP_ALWAYS_ON_COUNTER (only the same frequency), so changing this would 
break userspace expecting to be able to compare the value returned by 
MSM_PARAM_TIMESTAMP with CP timestamp values.

On 5/17/23 12:50 PM, Konrad Dybcio wrote:
> Use the always-on counter provided by the GMU to skip having to
> keep the GPU online.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>   drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index 8707e8b6ac7e..d2a999b90589 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -1664,12 +1664,9 @@ static int a6xx_get_timestamp(struct msm_gpu *gpu, uint64_t *value)
>   
>   	mutex_lock(&a6xx_gpu->gmu.lock);
>   
> -	/* Force the GPU power on so we can read this register */
> -	a6xx_gmu_set_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
> -
> -	*value = gpu_read64(gpu, REG_A6XX_CP_ALWAYS_ON_COUNTER);
> -
> -	a6xx_gmu_clear_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
> +	*value = gmu_read64(&a6xx_gpu->gmu,
> +			    REG_A6XX_GMU_ALWAYS_ON_COUNTER_L,
> +			    REG_A6XX_GMU_ALWAYS_ON_COUNTER_H);
>   
>   	mutex_unlock(&a6xx_gpu->gmu.lock);
>   
>
Konrad Dybcio May 17, 2023, 7:08 p.m. UTC | #2 
On 17.05.2023 20:09, Jonathan Marek wrote:
> AFAIK GMU_ALWAYS_ON_COUNTER does not have the same value as CP_ALWAYS_ON_COUNTER (only the same frequency), so changing this would break userspace expecting to be able to compare the value returned by MSM_PARAM_TIMESTAMP with CP timestamp values.
FWIW A630 and A730 seem to work fine with this patch. Anything
in particular I should look out for?

Konrad
> 
> On 5/17/23 12:50 PM, Konrad Dybcio wrote:
>> Use the always-on counter provided by the GMU to skip having to
>> keep the GPU online.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 9 +++------
>>   1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>> index 8707e8b6ac7e..d2a999b90589 100644
>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>> @@ -1664,12 +1664,9 @@ static int a6xx_get_timestamp(struct msm_gpu *gpu, uint64_t *value)
>>         mutex_lock(&a6xx_gpu->gmu.lock);
>>   -    /* Force the GPU power on so we can read this register */
>> -    a6xx_gmu_set_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
>> -
>> -    *value = gpu_read64(gpu, REG_A6XX_CP_ALWAYS_ON_COUNTER);
>> -
>> -    a6xx_gmu_clear_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
>> +    *value = gmu_read64(&a6xx_gpu->gmu,
>> +                REG_A6XX_GMU_ALWAYS_ON_COUNTER_L,
>> +                REG_A6XX_GMU_ALWAYS_ON_COUNTER_H);
>>         mutex_unlock(&a6xx_gpu->gmu.lock);
>>
Jonathan Marek May 17, 2023, 8:33 p.m. UTC | #3 
On 5/17/23 3:08 PM, Konrad Dybcio wrote:
> 
> 
> On 17.05.2023 20:09, Jonathan Marek wrote:
>> AFAIK GMU_ALWAYS_ON_COUNTER does not have the same value as CP_ALWAYS_ON_COUNTER (only the same frequency), so changing this would break userspace expecting to be able to compare the value returned by MSM_PARAM_TIMESTAMP with CP timestamp values.
> FWIW A630 and A730 seem to work fine with this patch. Anything
> in particular I should look out for?

mesa uses it for perfetto tracing to synchronize the GPU/CPU timelines.

> 
> Konrad
>>
>> On 5/17/23 12:50 PM, Konrad Dybcio wrote:
>>> Use the always-on counter provided by the GMU to skip having to
>>> keep the GPU online.
>>>
>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>>> ---
>>>    drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 9 +++------
>>>    1 file changed, 3 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> index 8707e8b6ac7e..d2a999b90589 100644
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> @@ -1664,12 +1664,9 @@ static int a6xx_get_timestamp(struct msm_gpu *gpu, uint64_t *value)
>>>          mutex_lock(&a6xx_gpu->gmu.lock);
>>>    -    /* Force the GPU power on so we can read this register */
>>> -    a6xx_gmu_set_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
>>> -
>>> -    *value = gpu_read64(gpu, REG_A6XX_CP_ALWAYS_ON_COUNTER);
>>> -
>>> -    a6xx_gmu_clear_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
>>> +    *value = gmu_read64(&a6xx_gpu->gmu,
>>> +                REG_A6XX_GMU_ALWAYS_ON_COUNTER_L,
>>> +                REG_A6XX_GMU_ALWAYS_ON_COUNTER_H);
>>>          mutex_unlock(&a6xx_gpu->gmu.lock);
>>>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 8707e8b6ac7e..d2a999b90589 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1664,12 +1664,9 @@  static int a6xx_get_timestamp(struct msm_gpu *gpu, uint64_t *value)
 
 	mutex_lock(&a6xx_gpu->gmu.lock);
 
-	/* Force the GPU power on so we can read this register */
-	a6xx_gmu_set_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
-
-	*value = gpu_read64(gpu, REG_A6XX_CP_ALWAYS_ON_COUNTER);
-
-	a6xx_gmu_clear_oob(&a6xx_gpu->gmu, GMU_OOB_PERFCOUNTER_SET);
+	*value = gmu_read64(&a6xx_gpu->gmu,
+			    REG_A6XX_GMU_ALWAYS_ON_COUNTER_L,
+			    REG_A6XX_GMU_ALWAYS_ON_COUNTER_H);
 
 	mutex_unlock(&a6xx_gpu->gmu.lock);