[Intel-gfx] [PATCH v2 06/20] drm/i915: Polish some dbuf debugs

[Lisovskiy, Stanislav]

On Tue, 2020-02-25 at 19:11 +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Polish some of the dbuf code to give more meaningful debug
> messages and whatnot. Also we can switch over to the per-device
> debugs/warns at the same time.
> 
> Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  .../drm/i915/display/intel_display_power.c    | 40 +++++++++------
> ----
>  1 file changed, 19 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 6e25a1317161..e81e561e8ac0 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -4433,11 +4433,12 @@ static void
> intel_power_domains_sync_hw(struct drm_i915_private *dev_priv)
>  	mutex_unlock(&power_domains->lock);
>  }
>  
> -static inline
> -bool intel_dbuf_slice_set(struct drm_i915_private *dev_priv,
> -			  i915_reg_t reg, bool enable)
> +static void intel_dbuf_slice_set(struct drm_i915_private *dev_priv,
> +				 enum dbuf_slice slice, bool enable)
>  {
> -	u32 val, status;
> +	i915_reg_t reg = DBUF_CTL_S(slice);
> +	bool state;
> +	u32 val;
>  
>  	val = intel_de_read(dev_priv, reg);
>  	val = enable ? (val | DBUF_POWER_REQUEST) : (val &
> ~DBUF_POWER_REQUEST);
> @@ -4445,13 +4446,10 @@ bool intel_dbuf_slice_set(struct
> drm_i915_private *dev_priv,
>  	intel_de_posting_read(dev_priv, reg);
>  	udelay(10);
>  
> -	status = intel_de_read(dev_priv, reg) & DBUF_POWER_STATE;
> -	if ((enable && !status) || (!enable && status)) {
> -		drm_err(&dev_priv->drm, "DBus power %s timeout!\n",
> -			enable ? "enable" : "disable");
> -		return false;
> -	}
> -	return true;
> +	state = intel_de_read(dev_priv, reg) & DBUF_POWER_STATE;
> +	drm_WARN(&dev_priv->drm, enable != state,
> +		 "DBuf slice %d power %s timeout!\n",
> +		 slice, enable ? "enable" : "disable");
>  }
>  
>  static void gen9_dbuf_enable(struct drm_i915_private *dev_priv)
> @@ -4467,14 +4465,16 @@ static void gen9_dbuf_disable(struct
> drm_i915_private *dev_priv)
>  void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
>  			    u8 req_slices)
>  {
> -	int i;
> -	int max_slices = INTEL_INFO(dev_priv)-
> >num_supported_dbuf_slices;
> +	int num_slices = INTEL_INFO(dev_priv)-
> >num_supported_dbuf_slices;
>  	struct i915_power_domains *power_domains = &dev_priv-
> >power_domains;
> +	enum dbuf_slice slice;
>  
> -	drm_WARN(&dev_priv->drm, hweight8(req_slices) > max_slices,
> -		 "Invalid number of dbuf slices requested\n");
> +	drm_WARN(&dev_priv->drm, req_slices & ~(BIT(num_slices) - 1),
> +		 "Invalid set of dbuf slices (0x%x) requested (num dbuf
> slices %d)\n",
> +		 req_slices, num_slices);
>  
> -	DRM_DEBUG_KMS("Updating dbuf slices to 0x%x\n", req_slices);
> +	drm_dbg_kms(&dev_priv->drm,
> +		    "Updating dbuf slices to 0x%x\n", req_slices);
>  
>  	/*
>  	 * Might be running this in parallel to
> gen9_dc_off_power_well_enable
> @@ -4485,11 +4485,9 @@ void icl_dbuf_slices_update(struct
> drm_i915_private *dev_priv,
>  	 */
>  	mutex_lock(&power_domains->lock);
>  
> -	for (i = 0; i < max_slices; i++) {
> -		intel_dbuf_slice_set(dev_priv,
> -				     DBUF_CTL_S(i),
> -				     (req_slices & BIT(i)) != 0);
> -	}
> +	for (slice = DBUF_S1; slice < num_slices; slice++)
> +		intel_dbuf_slice_set(dev_priv, slice,
> +				     req_slices & BIT(slice));

Would be cool to completely get rid of any magic numbers or
definitions, 0 in a sense is more universal here than DBUF_S1.

If we are counting slices as numbers it seems logical that we 
iterate [0..num_slices) range. If you want to name the first slice
explicitly then it probably has to be something like iterator
logic, i.e for (slice = FIRST_SLICE; slice != LAST_SLICE; slice++).

But trying to name it at the same time with comparing to total _amount_
looks a bit confusing.

Stan

>  
>  	dev_priv->enabled_dbuf_slices_mask = req_slices;
>