[Intel-gfx] [PATCH] drm/i915: Show actual along side request frequency in debugfs/i915_rps_boost_info

[Tvrtko Ursulin]

On 02/10/2018 09:36, Chris Wilson wrote:
> Previously we hesitated in adding the hw probe for the actual GPU
> frequency for rps_boost as it is quite cumbersome, but given some
> surprising HW behaviour it would be useful to know both the RPS boost
> state and the actual HW state in one location.
> 
> Reported-by: Tomi Sarvela <tomi.p.sarvela at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_debugfs.c | 19 +++++++++++++++++--
>   1 file changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index b4744a68cd88..ce17a53b3a66 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2215,8 +2215,22 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
>   	struct drm_i915_private *dev_priv = node_to_i915(m->private);
>   	struct drm_device *dev = &dev_priv->drm;
>   	struct intel_rps *rps = &dev_priv->gt_pm.rps;
> +	u32 act_freq = rps->cur_freq;
>   	struct drm_file *file;
>   
> +	if (intel_runtime_pm_get_if_in_use(dev_priv)) {
> +		if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
> +			mutex_lock(&dev_priv->pcu_lock);
> +			act_freq = vlv_punit_read(dev_priv,
> +						  PUNIT_REG_GPU_FREQ_STS);

There is another read site for this reg which right shifts and masks 
before passing to intel_gpu_freq. Who is right and who is wrong? :)

Regards,

Tvrtko`

> +			mutex_unlock(&dev_priv->pcu_lock);
> +		} else {
> +			act_freq = intel_get_cagf(dev_priv,
> +						  I915_READ(GEN6_RPSTAT1));
> +		}
> +		intel_runtime_pm_put(dev_priv);
> +	}
> +
>   	seq_printf(m, "RPS enabled? %d\n", rps->enabled);
>   	seq_printf(m, "GPU busy? %s [%d requests]\n",
>   		   yesno(dev_priv->gt.awake), dev_priv->gt.active_requests);
> @@ -2224,8 +2238,9 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
>   	seq_printf(m, "Boosts outstanding? %d\n",
>   		   atomic_read(&rps->num_waiters));
>   	seq_printf(m, "Interactive? %d\n", READ_ONCE(rps->power.interactive));
> -	seq_printf(m, "Frequency requested %d\n",
> -		   intel_gpu_freq(dev_priv, rps->cur_freq));
> +	seq_printf(m, "Frequency requested %d, actual %d\n",
> +		   intel_gpu_freq(dev_priv, rps->cur_freq),
> +		   intel_gpu_freq(dev_priv, act_freq));
>   	seq_printf(m, "  min hard:%d, soft:%d; max soft:%d, hard:%d\n",
>   		   intel_gpu_freq(dev_priv, rps->min_freq),
>   		   intel_gpu_freq(dev_priv, rps->min_freq_softlimit),
>