[v2] drm/msm: adreno: add support for DDR bandwidth scaling via GMU

[PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Neil Armstrong 3 days, 14 hours ago

The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth
along the Frequency and Power Domain level, but by default we leave the
OPP core vote for the interconnect ddr path.

While scaling via the interconnect path was sufficient, newer GPUs
like the A750 requires specific vote paremeters and bandwidth to
achieve full functionality.

While the feature will require some data in a6xx_info, it's safer
to only enable tested platforms with this flag first.

Add a new feature enabling DDR Bandwidth vote via GMU.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -58,6 +58,7 @@ enum adreno_family {
 #define ADRENO_FEAT_HAS_HW_APRIV		BIT(0)
 #define ADRENO_FEAT_HAS_CACHED_COHERENT		BIT(1)
 #define ADRENO_FEAT_PREEMPTION			BIT(2)
+#define ADRENO_FEAT_GMU_BW_VOTE			BIT(3)
 
 /* Helper for formating the chip_id in the way that userspace tools like
  * crashdec expect.

-- 
2.34.1

Re: [PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Rob Clark 1 day, 12 hours ago

On Tue, Nov 19, 2024 at 9:56 AM Neil Armstrong
<neil.armstrong@linaro.org> wrote:
>
> The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth

nit, s/GNU/GMU/

> along the Frequency and Power Domain level, but by default we leave the
> OPP core vote for the interconnect ddr path.
>
> While scaling via the interconnect path was sufficient, newer GPUs
> like the A750 requires specific vote paremeters and bandwidth to
> achieve full functionality.
>
> While the feature will require some data in a6xx_info, it's safer
> to only enable tested platforms with this flag first.
>
> Add a new feature enabling DDR Bandwidth vote via GMU.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> @@ -58,6 +58,7 @@ enum adreno_family {
>  #define ADRENO_FEAT_HAS_HW_APRIV               BIT(0)
>  #define ADRENO_FEAT_HAS_CACHED_COHERENT                BIT(1)
>  #define ADRENO_FEAT_PREEMPTION                 BIT(2)
> +#define ADRENO_FEAT_GMU_BW_VOTE                        BIT(3)
>
>  /* Helper for formating the chip_id in the way that userspace tools like
>   * crashdec expect.
>
> --
> 2.34.1
>

Re: [PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Rob Clark 1 day, 12 hours ago

On Thu, Nov 21, 2024 at 11:50 AM Rob Clark <robdclark@gmail.com> wrote:
>
> On Tue, Nov 19, 2024 at 9:56 AM Neil Armstrong
> <neil.armstrong@linaro.org> wrote:
> >
> > The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth
>
> nit, s/GNU/GMU/

And I guess you meant "GPU Management Unit" (presumably this isn't yet
another recursive acronym

Same comment in the next commit

>
> > along the Frequency and Power Domain level, but by default we leave the
> > OPP core vote for the interconnect ddr path.
> >
> > While scaling via the interconnect path was sufficient, newer GPUs
> > like the A750 requires specific vote paremeters and bandwidth to
> > achieve full functionality.
> >
> > While the feature will require some data in a6xx_info, it's safer
> > to only enable tested platforms with this flag first.
> >
> > Add a new feature enabling DDR Bandwidth vote via GMU.
> >
> > Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> > ---
> >  drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
> > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > @@ -58,6 +58,7 @@ enum adreno_family {
> >  #define ADRENO_FEAT_HAS_HW_APRIV               BIT(0)
> >  #define ADRENO_FEAT_HAS_CACHED_COHERENT                BIT(1)
> >  #define ADRENO_FEAT_PREEMPTION                 BIT(2)
> > +#define ADRENO_FEAT_GMU_BW_VOTE                        BIT(3)
> >
> >  /* Helper for formating the chip_id in the way that userspace tools like
> >   * crashdec expect.
> >
> > --
> > 2.34.1
> >

Re: [PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Dmitry Baryshkov 2 days, 21 hours ago

On Tue, Nov 19, 2024 at 06:56:39PM +0100, Neil Armstrong wrote:
> The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth
> along the Frequency and Power Domain level, but by default we leave the
> OPP core vote for the interconnect ddr path.
> 
> While scaling via the interconnect path was sufficient, newer GPUs
> like the A750 requires specific vote paremeters and bandwidth to
> achieve full functionality.
> 
> While the feature will require some data in a6xx_info, it's safer
> to only enable tested platforms with this flag first.
> 
> Add a new feature enabling DDR Bandwidth vote via GMU.

Squash into the implementation patch.

> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> @@ -58,6 +58,7 @@ enum adreno_family {
>  #define ADRENO_FEAT_HAS_HW_APRIV		BIT(0)
>  #define ADRENO_FEAT_HAS_CACHED_COHERENT		BIT(1)
>  #define ADRENO_FEAT_PREEMPTION			BIT(2)
> +#define ADRENO_FEAT_GMU_BW_VOTE			BIT(3)
>  
>  /* Helper for formating the chip_id in the way that userspace tools like
>   * crashdec expect.
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry

Re: [PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Neil Armstrong 2 days, 19 hours ago

On 20/11/2024 12:19, Dmitry Baryshkov wrote:
> On Tue, Nov 19, 2024 at 06:56:39PM +0100, Neil Armstrong wrote:
>> The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth
>> along the Frequency and Power Domain level, but by default we leave the
>> OPP core vote for the interconnect ddr path.
>>
>> While scaling via the interconnect path was sufficient, newer GPUs
>> like the A750 requires specific vote paremeters and bandwidth to
>> achieve full functionality.
>>
>> While the feature will require some data in a6xx_info, it's safer
>> to only enable tested platforms with this flag first.
>>
>> Add a new feature enabling DDR Bandwidth vote via GMU.
> 
> Squash into the implementation patch.

Which one ? the flag is use in the next 3 patches

> 
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
>> index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
>> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
>> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
>> @@ -58,6 +58,7 @@ enum adreno_family {
>>   #define ADRENO_FEAT_HAS_HW_APRIV		BIT(0)
>>   #define ADRENO_FEAT_HAS_CACHED_COHERENT		BIT(1)
>>   #define ADRENO_FEAT_PREEMPTION			BIT(2)
>> +#define ADRENO_FEAT_GMU_BW_VOTE			BIT(3)
>>   
>>   /* Helper for formating the chip_id in the way that userspace tools like
>>    * crashdec expect.
>>
>> -- 
>> 2.34.1
>>
>

Re: [PATCH v2 04/11] drm/msm: adreno: add GMU_BW_VOTE feature flag

Posted by Dmitry Baryshkov 1 day, 13 hours ago

On Wed, Nov 20, 2024 at 01:37:48PM +0100, Neil Armstrong wrote:
> On 20/11/2024 12:19, Dmitry Baryshkov wrote:
> > On Tue, Nov 19, 2024 at 06:56:39PM +0100, Neil Armstrong wrote:
> > > The Adreno GMU Management Unit (GNU) can also scale the DDR Bandwidth
> > > along the Frequency and Power Domain level, but by default we leave the
> > > OPP core vote for the interconnect ddr path.
> > > 
> > > While scaling via the interconnect path was sufficient, newer GPUs
> > > like the A750 requires specific vote paremeters and bandwidth to
> > > achieve full functionality.
> > > 
> > > While the feature will require some data in a6xx_info, it's safer
> > > to only enable tested platforms with this flag first.
> > > 
> > > Add a new feature enabling DDR Bandwidth vote via GMU.
> > 
> > Squash into the implementation patch.
> 
> Which one ? the flag is use in the next 3 patches

First one which uses it

> 
> > 
> > > 
> > > Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> > > ---
> > >   drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
> > >   1 file changed, 1 insertion(+)
> > > 
> > > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > > index 4702d4cfca3b58fb3cbb25cb6805f1c19be2ebcb..394b96eb6c83354ae008b15b562bedb96cd391dd 100644
> > > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > > @@ -58,6 +58,7 @@ enum adreno_family {
> > >   #define ADRENO_FEAT_HAS_HW_APRIV		BIT(0)
> > >   #define ADRENO_FEAT_HAS_CACHED_COHERENT		BIT(1)
> > >   #define ADRENO_FEAT_PREEMPTION			BIT(2)
> > > +#define ADRENO_FEAT_GMU_BW_VOTE			BIT(3)
> > >   /* Helper for formating the chip_id in the way that userspace tools like
> > >    * crashdec expect.
> > > 
> > > -- 
> > > 2.34.1
> > > 
> > 
> 

-- 
With best wishes
Dmitry