[0/2] Prune unsupported modes as per HDMI2.1 spec

Message

Nautiyal, Ankit K May 9, 2022, 9:31 a.m. UTC

Modes like 4K100, 4K120, 8K50, 8K60 need FRL and/or DSC from source.
Since FRL and DSC are not currently supported natively by intel
platforms (are supported only via DP-HDMI2.1 PCONs), these modes must
be pruned as per spec.
Currently these modes are not getting pruned as we check the TMDS clock,
which passes some of these with YCbCr420 format and with lower bpc.
This causes failures during compliance test (e.g. HFR1-67).

This patch prunes the modes, if FRL, DSC not supported, or the support
requirement not met as per the spec.
Although the spec mentions 4K100, 4K120, 8K50, and 8K60 video timings,
I have used the check for clock >= 2376 MHz (or 1188 MHz with 420
format), instead of using individual VICs.

While at it, fix a bug while parsing the compressed bpc supported
from edid.

Ankit Nautiyal (2):
  drm/edid: Fix minimum bpc supported with DSC1.2 for HDMI sink
  drm/i915/hdmi: Prune unsupported modes as per HDMI2.1 spec

 drivers/gpu/drm/drm_edid.c                |  3 +-
 drivers/gpu/drm/i915/display/intel_hdmi.c | 48 +++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)