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

[Sripada, Radhakrishna]

Merged. Thank you for the review.

--Radhakrishna(RK) Sripada

> -----Original Message-----
> From: Taylor, Clinton A <clinton.a.taylor at intel.com>
> Sent: Tuesday, June 20, 2023 2:10 PM
> To: Sripada, Radhakrishna <radhakrishna.sripada at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Lee, Shawn C <shawn.c.lee at intel.com>; Almahallawy, Khaled
> <khaled.almahallawy at intel.com>
> Subject: Re: [PATCH] drm/i915/mtl: Skip using vbt hdmi_level_shifter selection
> on MTL
> 
> 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;