[Intel-gfx] [PATCH] drm/i915/mtl: Skip using vbt hdmi_level_shifter selection on MTL

[Taylor, Clinton A]

On Fri, 2023-06-16 at 14:00 -0700, Radhakrishna Sripada wrote:
> The hdmi_level_shifter part of General Bytes definition in VBT, which was
> used for choosing different levels on earlier platforms is now a hidden
> optin and shows the default value of 0. The level shifter is now to be
> deduced from hdmi_default_entry in  intel_ddi_buf_trans for each phy.
> 
> Skip providing the default hw provided value to force driver to choose hdmi
> default entry.
> 
> Bspec: 20124
> Cc: Khaled Almahallawy <khaled.almahallawy at intel.com>
> Cc: Lee Shawn C <shawn.c.lee at intel.com>
> Cc: Clint Taylor <Clinton.A.Taylor at intel.com>
> Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_bios.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
> b/drivers/gpu/drm/i915/display/intel_bios.c
> index 34a397adbd6b..4b9bf76e137d 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -2615,7 +2615,8 @@ intel_bios_encoder_is_lspcon(const struct intel_bios_encoder_data
> *devdata)
>  /* This is an index in the HDMI/DVI DDI buffer translation table, or -1 */
>  int intel_bios_hdmi_level_shift(const struct intel_bios_encoder_data *devdata)
>  {
> -	if (!devdata || devdata->i915->display.vbt.version < 158)
> +	if (!devdata || devdata->i915->display.vbt.version < 158 ||
> +	    DISPLAY_VER(devdata->i915) >= 14)
>  		return -1;
>  
Reviewed-by: Clint Taylor <Clinton.A.Taylor at intel.com>

-Clint

>  	return devdata->child.hdmi_level_shifter_value;