Re: [PATCH] drm/radeon/dpm: add debugfs support for RS780/RS880 (v2)

[Anthoine Bourgeois <anthoine.bourgeois@gmail.com>]

On Wed, Jul 17, 2013 at 09:44:00PM +0000, Deucher, Alexander wrote:
>> -----Original Message-----
>> From: Anthoine Bourgeois [mailto:anthoine.bourgeois@gmail.com]
>> Sent: Wednesday, July 17, 2013 5:23 PM
>> To: Deucher, Alexander; Koenig, Christian; Jerome Glisse
>> Cc: dri-devel@lists.freedesktop.org
>> Subject: Re: [PATCH] drm/radeon/dpm: add debugfs support for
>> RS780/RS880 (v2)
>>
>> On Wed, Jul 17, 2013 at 08:54:33PM +0000, Deucher, Alexander wrote:
>> >Good catch, I screwed up the ref divider calculation.  How about the
>> attached patch?
>>
>> It works too. But here was my logic, tell me if I'm wrong:
>
>Ok.
>
>>
>> The output frequency of the PLL is equal to the VCO frequency (FVCO)
>> divided by the post-scale counter (C).
>> Fout = FVCO / C
>> And VCO frequency is equal to feedback (M) times the reference frequency
>> (FREF).
>> FVCO = FREF x M
>> Where reference clock (FREF) is equal to the input clock (Fin) divided
>> by the pre-scale counter (N)
>> FREF = Fin / N
>> then
>> FVCO = Fin x M / N
>> and
>> Fout = (Fin x M) / (N x C) = FREF x M / C
>>
>> where:
>> FVCO = VCO frequency
>> Fin = input frequency
>> Fout = output frequency
>> FREF = reference frequency (rdev->clock.spll.reference_freq in the code)
>> M = counter (multiplier), part of the clock feedback path (current_fb_div)
>> N = counter (divider), part of the clock reference path (ref_div)
>> C = post-scale counter (divider) (post_div)
>>
>> No need to ref_div. Or reference_freq == Fin and the varname confuses me
>> ?
>
>I'm not sure exactly how the PLL is set up.  The calculation looks like so:
>
>Output frequency =  (reference freq * feedback divider) / (reference divider * post divider);
>
>I think FVCO = (FREF * M) / N to use your terms, but I'm not really a hw expert.

Neither me. I trust you, then :

Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@gmail.com>

on v3.

Anthoine

>
>Alex
>
>>
>> In my test:
>> # cat /sys/kernel/debug/dri/0/radeon_pm_info
>> uvd    vclk: 0 dclk: 0
>> power level 0    sclk: 20000 vddc_index: 2
>>
>> when my system is idle and sclk == 19690 and:
>> # cat /sys/kernel/debug/dri/0/radeon_pm_info
>> uvd    vclk: 0 dclk: 0
>> power level 1    sclk: 50000 vddc_index: 2
>>
>> when I play supertuxkart with sclk == 49762.
>>
>> Thanks for yesturday, I was in a wrong way,
>> Anthoine
>>
>> >
>> >Alex
>> >
>> >> -----Original Message-----
>> >> From: Anthoine Bourgeois [mailto:anthoine.bourgeois@gmail.com]
>> >> Sent: Wednesday, July 17, 2013 4:43 PM
>> >> To: Deucher, Alexander; Koenig, Christian; Jerome Glisse; Anthoine
>> >> Bourgeois
>> >> Cc: dri-devel@lists.freedesktop.org
>> >> Subject: [PATCH] drm/radeon/dpm: add debugfs support for
>> RS780/RS880
>> >> (v2)
>> >>
>> >> This allows you to look at the current DPM state via
>> >> debugfs.
>> >>
>> >> Due to the way the hardware works on these asics, there's
>> >> no way to look up exactly what power state we are in, so
>> >> we make the best guess we can based on the current sclk.
>> >>
>> >> v2: fix sclk equation
>> >>
>> >> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
>> >> Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@gmail.com>
>> >> ---
>> >>  drivers/gpu/drm/radeon/radeon_asic.c |  1 +
>> >>  drivers/gpu/drm/radeon/radeon_asic.h |  2 ++
>> >>  drivers/gpu/drm/radeon/rs780_dpm.c   | 23
>> +++++++++++++++++++++++
>> >>  drivers/gpu/drm/radeon/rs780d.h      |  3 +++
>> >>  4 files changed, 29 insertions(+)
>> >>
>> >> diff --git a/drivers/gpu/drm/radeon/radeon_asic.c
>> >> b/drivers/gpu/drm/radeon/radeon_asic.c
>> >> index fea997e..78bec1a 100644
>> >> --- a/drivers/gpu/drm/radeon/radeon_asic.c
>> >> +++ b/drivers/gpu/drm/radeon/radeon_asic.c
>> >> @@ -1270,6 +1270,7 @@ static struct radeon_asic rs780_asic = {
>> >>  		.get_sclk = &rs780_dpm_get_sclk,
>> >>  		.get_mclk = &rs780_dpm_get_mclk,
>> >>  		.print_power_state = &rs780_dpm_print_power_state,
>> >> +		.debugfs_print_current_performance_level =
>> >> &rs780_dpm_debugfs_print_current_performance_level,
>> >>  	},
>> >>  	.pflip = {
>> >>  		.pre_page_flip = &rs600_pre_page_flip,
>> >> diff --git a/drivers/gpu/drm/radeon/radeon_asic.h
>> >> b/drivers/gpu/drm/radeon/radeon_asic.h
>> >> index b04b578..ca18957 100644
>> >> --- a/drivers/gpu/drm/radeon/radeon_asic.h
>> >> +++ b/drivers/gpu/drm/radeon/radeon_asic.h
>> >> @@ -433,6 +433,8 @@ u32 rs780_dpm_get_sclk(struct radeon_device
>> *rdev,
>> >> bool low);
>> >>  u32 rs780_dpm_get_mclk(struct radeon_device *rdev, bool low);
>> >>  void rs780_dpm_print_power_state(struct radeon_device *rdev,
>> >>  				 struct radeon_ps *ps);
>> >> +void rs780_dpm_debugfs_print_current_performance_level(struct
>> >> radeon_device *rdev,
>> >> +						       struct seq_file *m);
>> >>
>> >>  /* uvd */
>> >>  int r600_uvd_init(struct radeon_device *rdev);
>> >> diff --git a/drivers/gpu/drm/radeon/rs780_dpm.c
>> >> b/drivers/gpu/drm/radeon/rs780_dpm.c
>> >> index bef832a..7f128c2 100644
>> >> --- a/drivers/gpu/drm/radeon/rs780_dpm.c
>> >> +++ b/drivers/gpu/drm/radeon/rs780_dpm.c
>> >> @@ -28,6 +28,7 @@
>> >>  #include "r600_dpm.h"
>> >>  #include "rs780_dpm.h"
>> >>  #include "atom.h"
>> >> +#include <linux/seq_file.h>
>> >>
>> >>  static struct igp_ps *rs780_get_ps(struct radeon_ps *rps)
>> >>  {
>> >> @@ -961,3 +962,25 @@ u32 rs780_dpm_get_mclk(struct radeon_device
>> >> *rdev, bool low)
>> >>
>> >>  	return pi->bootup_uma_clk;
>> >>  }
>> >> +
>> >> +void rs780_dpm_debugfs_print_current_performance_level(struct
>> >> radeon_device *rdev,
>> >> +						       struct seq_file *m)
>> >> +{
>> >> +	struct radeon_ps *rps = rdev->pm.dpm.current_ps;
>> >> +	struct igp_ps *ps = rs780_get_ps(rps);
>> >> +	u32 current_fb_div = RREG32(FVTHROT_STATUS_REG0) &
>> >> CURRENT_FEEDBACK_DIV_MASK;
>> >> +	u32 func_cntl = RREG32(CG_SPLL_FUNC_CNTL);
>> >> +	u32 post_div = ((func_cntl & SPLL_SW_HILEN_MASK) >>
>> >> SPLL_SW_HILEN_SHIFT) + 1 +
>> >> +		((func_cntl & SPLL_SW_LOLEN_MASK) >>
>> >> SPLL_SW_LOLEN_SHIFT) + 1;
>> >> +	u32 sclk = (rdev->clock.spll.reference_freq * current_fb_div) /
>> >> post_div;
>> >> +
>> >> +	seq_printf(m, "uvd    vclk: %d dclk: %d\n", rps->vclk, rps->dclk);
>> >> +
>> >> +	/* guess based on the current sclk */
>> >> +	if (sclk < (ps->sclk_low + 500))
>> >> +		seq_printf(m, "power level 0    sclk: %u vddc_index: %d\n",
>> >> +			   ps->sclk_low, ps->min_voltage);
>> >> +	else
>> >> +		seq_printf(m, "power level 1    sclk: %u vddc_index: %d\n",
>> >> +			   ps->sclk_high, ps->max_voltage);
>> >> +}
>> >> diff --git a/drivers/gpu/drm/radeon/rs780d.h
>> >> b/drivers/gpu/drm/radeon/rs780d.h
>> >> index b1142ed..cfbe9a4 100644
>> >> --- a/drivers/gpu/drm/radeon/rs780d.h
>> >> +++ b/drivers/gpu/drm/radeon/rs780d.h
>> >> @@ -28,6 +28,7 @@
>> >>  #       define SPLL_SLEEP                                (1 << 1)
>> >>  #       define SPLL_REF_DIV(x)                           ((x) << 2)
>> >>  #       define SPLL_REF_DIV_MASK                         (7 << 2)
>> >> +#       define SPLL_REF_DIV_SHIFT                        2
>> >>  #       define SPLL_FB_DIV(x)                            ((x) << 5)
>> >>  #       define SPLL_FB_DIV_MASK                          (0xff << 2)
>> >>  #       define SPLL_FB_DIV_SHIFT                         2
>> >> @@ -36,8 +37,10 @@
>> >>  #       define SPLL_PULSENUM_MASK                        (3 << 14)
>> >>  #       define SPLL_SW_HILEN(x)                          ((x) << 16)
>> >>  #       define SPLL_SW_HILEN_MASK                        (0xf << 16)
>> >> +#       define SPLL_SW_HILEN_SHIFT                       16
>> >>  #       define SPLL_SW_LOLEN(x)                          ((x) << 20)
>> >>  #       define SPLL_SW_LOLEN_MASK                        (0xf << 20)
>> >> +#       define SPLL_SW_LOLEN_SHIFT                       20
>> >>  #       define SPLL_DIVEN                                (1 << 24)
>> >>  #       define SPLL_BYPASS_EN                            (1 << 25)
>> >>  #       define SPLL_CHG_STATUS                           (1 << 29)
>> >> --
>> >> 1.8.1.5
>> >>
>> >
>>
>>
>
>