[Intel-gfx] [PATCH] drm/i915: Read DIMM size in Gb rather than GB

[Souza, Jose]

On Tue, 2020-09-29 at 16:13 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <
> ville.syrjala at linux.intel.com
> >
> 
> CNL+ can report DIMM sizes in .5 GB units. In order to not trauncate
> away the .5 GB let's switch to storing the DIMM size in Gb units.
> 

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> Cc: Swati Sharma <
> swati2.sharma at intel.com
> >
> Signed-off-by: Ville Syrjälä <
> ville.syrjala at linux.intel.com
> >
> ---
>  drivers/gpu/drm/i915/intel_dram.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dram.c b/drivers/gpu/drm/i915/intel_dram.c
> index 8aa12cad93ce..4754296a250e 100644
> --- a/drivers/gpu/drm/i915/intel_dram.c
> +++ b/drivers/gpu/drm/i915/intel_dram.c
> @@ -7,7 +7,8 @@
>  #include "intel_dram.h"
>  
>  struct dram_dimm_info {
> -	u8 size, width, ranks;
> +	u16 size;
> +	u8 width, ranks;
>  };
>  
>  struct dram_channel_info {
> @@ -41,10 +42,10 @@ static int intel_dimm_num_devices(const struct dram_dimm_info *dimm)
>  	return dimm->ranks * 64 / (dimm->width ?: 1);
>  }
>  
> -/* Returns total GB for the whole DIMM */
> +/* Returns total Gb for the whole DIMM */
>  static int skl_get_dimm_size(u16 val)
>  {
> -	return val & SKL_DRAM_SIZE_MASK;
> +	return (val & SKL_DRAM_SIZE_MASK) * 8;
>  }
>  
>  static int skl_get_dimm_width(u16 val)
> @@ -74,10 +75,10 @@ static int skl_get_dimm_ranks(u16 val)
>  	return val + 1;
>  }
>  
> -/* Returns total GB for the whole DIMM */
> +/* Returns total Gb for the whole DIMM */
>  static int cnl_get_dimm_size(u16 val)
>  {
> -	return (val & CNL_DRAM_SIZE_MASK) / 2;
> +	return (val & CNL_DRAM_SIZE_MASK) * 8 / 2;
>  }
>  
>  static int cnl_get_dimm_width(u16 val)
> @@ -110,8 +111,8 @@ static int cnl_get_dimm_ranks(u16 val)
>  static bool
>  skl_is_16gb_dimm(const struct dram_dimm_info *dimm)
>  {
> -	/* Convert total GB to Gb per DRAM device */
> -	return 8 * dimm->size / (intel_dimm_num_devices(dimm) ?: 1) == 16;
> +	/* Convert total Gb to Gb per DRAM device */
> +	return dimm->size / (intel_dimm_num_devices(dimm) ?: 1) == 16;
>  }
>  
>  static void
> @@ -130,7 +131,7 @@ skl_dram_get_dimm_info(struct drm_i915_private *i915,
>  	}
>  
>  	drm_dbg_kms(&i915->drm,
> -		    "CH%u DIMM %c size: %u GB, width: X%u, ranks: %u, 16Gb DIMMs: %s\n",
> +		    "CH%u DIMM %c size: %u Gb, width: X%u, ranks: %u, 16Gb DIMMs: %s\n",
>  		    channel, dimm_name, dimm->size, dimm->width, dimm->ranks,
>  		    yesno(skl_is_16gb_dimm(dimm)));
>  }
> @@ -354,9 +355,9 @@ static void bxt_get_dimm_info(struct dram_dimm_info *dimm, u32 val)
>  
>  	/*
>  	 * Size in register is Gb per DRAM device. Convert to total
> -	 * GB to match the way we report this for non-LP platforms.
> +	 * Gb to match the way we report this for non-LP platforms.
>  	 */
> -	dimm->size = bxt_get_dimm_size(val) * intel_dimm_num_devices(dimm) / 8;
> +	dimm->size = bxt_get_dimm_size(val) * intel_dimm_num_devices(dimm);
>  }
>  
>  static int bxt_get_dram_info(struct drm_i915_private *i915)
> @@ -404,7 +405,7 @@ static int bxt_get_dram_info(struct drm_i915_private *i915)
>  			    dram_info->type != type);
>  
>  		drm_dbg_kms(&i915->drm,
> -			    "CH%u DIMM size: %u GB, width: X%u, ranks: %u, type: %s\n",
> +			    "CH%u DIMM size: %u Gb, width: X%u, ranks: %u, type: %s\n",
>  			    i - BXT_D_CR_DRP0_DUNIT_START,
>  			    dimm.size, dimm.width, dimm.ranks,
>  			    intel_dram_type_str(type));
>