Re: [PATCH 07/14] drm/i915: Add bigjoiner and uncompressed joiner hw readout sanity checks

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Sep 06, 2024 at 06:28:00PM +0530, Ankit Nautiyal wrote:
> From: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> 
> Adding sanity checks for primary and secondary bigjoiner/uncompressed
> bitmasks, should make it easier to spot possible issues.
> 
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 24 ++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index cdc7531311fc..6f098383479f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -3638,11 +3638,17 @@ static void enabled_bigjoiner_pipes(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> +static u8 expected_secondary_pipes(u8 primary_pipes)
> +{
> +	return primary_pipes << 1;
> +}

Extracting this should be a separate patch really since it
was already in the code until the previous patch erroneously
removed it.

> +
>  static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
>  				 u8 *primary_pipes, u8 *secondary_pipes)
>  {
>  	u8 primary_uncompressed_joiner_pipes, primary_bigjoiner_pipes;
>  	u8 secondary_uncompressed_joiner_pipes, secondary_bigjoiner_pipes;
> +	u8 uncompressed_joiner_pipes, bigjoiner_pipes;
>  
>  	enabled_uncompressed_joiner_pipes(dev_priv, &primary_uncompressed_joiner_pipes,
>  					  &secondary_uncompressed_joiner_pipes);
> @@ -3650,6 +3656,24 @@ static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
>  	enabled_bigjoiner_pipes(dev_priv, &primary_bigjoiner_pipes,
>  				&secondary_bigjoiner_pipes);
>  
> +	uncompressed_joiner_pipes = primary_uncompressed_joiner_pipes |
> +				    secondary_uncompressed_joiner_pipes;
> +	bigjoiner_pipes = primary_bigjoiner_pipes | secondary_bigjoiner_pipes;
> +
> +	drm_WARN(&dev_priv->drm, (uncompressed_joiner_pipes & bigjoiner_pipes) != 0,
> +		 "Uncomressed joiner pipes(%x) and bigjoiner pipes(%x) can't intersect\n",
> +		 uncompressed_joiner_pipes, bigjoiner_pipes);

Please use 0x%x for printing hex numbers

Side note: maybe we should switch to the standard %#x instead?
Though we'd need to double check whether prink() follows the
idiotic C standard or not:
 printf("%#x", 1) -> 0x1, for any non-zero value
 bs.
 printf("%#x", 0) -> 0 (sigh)

If printk() behaves the same way then I want to see %#x anywhere
(pretty sure we do use it in a few places already though).


> +	drm_WARN(&dev_priv->drm, secondary_bigjoiner_pipes !=
> +		 expected_secondary_pipes(primary_bigjoiner_pipes),
> +		 "Wrong secondary bigjoiner pipes(expected %x, current %x)\n",
> +		 expected_secondary_pipes(primary_bigjoiner_pipes),
> +		 secondary_bigjoiner_pipes);
> +	drm_WARN(&dev_priv->drm, secondary_uncompressed_joiner_pipes !=
> +		 expected_secondary_pipes(primary_uncompressed_joiner_pipes),
> +		 "Wrong secondary uncompressed joiner pipes(expected %x, current %x)\n",
> +		 expected_secondary_pipes(primary_uncompressed_joiner_pipes),
> +		 secondary_uncompressed_joiner_pipes);
> +
>  	*primary_pipes = 0;
>  	*secondary_pipes = 0;
>  
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel