[PATCH 02/22] drm/radeon/dpm: add new callbacks to get the current sclk/mclk

[Christian König]

Am 02.10.2014 um 15:06 schrieb Alex Deucher:
> On Thu, Oct 2, 2014 at 8:26 AM, Christian König <deathsimple at vodafone.de> wrote:
>> Might be a good idea to make that a bit more generic, e.g. add a
>> get_current_clk callback and and a type (sclk, mclk, vclk, dclk, etc..)
>> enum. But I can live with this approach as well.
>>
> Yeah, I thought about that, but I'm not sure if there is a good way to
> query that for certain clocks when dynamic clocking is enabled.  E.g.,
> UVD on newer asics.

That's why I always favored using the PLL test registers. It can 
actually measure the clocks quite precisely if the reference clock 
(usually the PCI clock) is stable enough. And as far as I know can 
access any clock signal in the system, even the memory clock is 
measurable for each memory interface separately.

Christian.

>
> Alex
>
>> Christian.
>>
>> Am 01.10.2014 um 17:38 schrieb Alex Deucher:
>>
>>> Needed to to expose the current clocks via the INFO ioctl.
>>>
>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>> ---
>>>    drivers/gpu/drm/radeon/radeon.h | 4 ++++
>>>    1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/radeon/radeon.h
>>> b/drivers/gpu/drm/radeon/radeon.h
>>> index 510fe96..9e3dc82 100644
>>> --- a/drivers/gpu/drm/radeon/radeon.h
>>> +++ b/drivers/gpu/drm/radeon/radeon.h
>>> @@ -1935,6 +1935,8 @@ struct radeon_asic {
>>>                  bool (*vblank_too_short)(struct radeon_device *rdev);
>>>                  void (*powergate_uvd)(struct radeon_device *rdev, bool
>>> gate);
>>>                  void (*enable_bapm)(struct radeon_device *rdev, bool
>>> enable);
>>> +               u32 (*get_current_sclk)(struct radeon_device *rdev);
>>> +               u32 (*get_current_mclk)(struct radeon_device *rdev);
>>>          } dpm;
>>>          /* pageflipping */
>>>          struct {
>>> @@ -2893,6 +2895,8 @@ static inline void radeon_ring_write(struct
>>> radeon_ring *ring, uint32_t v)
>>>    #define radeon_dpm_vblank_too_short(rdev)
>>> rdev->asic->dpm.vblank_too_short((rdev))
>>>    #define radeon_dpm_powergate_uvd(rdev, g)
>>> rdev->asic->dpm.powergate_uvd((rdev), (g))
>>>    #define radeon_dpm_enable_bapm(rdev, e)
>>> rdev->asic->dpm.enable_bapm((rdev), (e))
>>> +#define radeon_dpm_get_current_sclk(rdev)
>>> rdev->asic->dpm.get_current_sclk((rdev))
>>> +#define radeon_dpm_get_current_mclk(rdev)
>>> rdev->asic->dpm.get_current_mclk((rdev))
>>>      /* Common functions */
>>>    /* AGP */
>>