[v2,0/3] Get dsc optimal output bpp

Message

Nautiyal, Ankit K Oct. 20, 2022, 12:44 p.m. UTC

Currently, when going with DSC for DP, we take the max lane, rate
and pipe bpp, to get the maximum compressed bpp possible. We then
set the output bpp to this value. It might be possible to have lesser
rate or lane count, for which the same compressed bpp works.

This RFC series attempts to get the best compressed bpp such that we
have maximum bpc, with minimum link rate and lane possible.

The policy here is chosen such that 'best compressed bpp' mean minimum
compression, ie. maximum compressed bpp. It means compress only that
is sufficient to sent over the link, and for that compressed bpp,
use minimum lanes, and rate.

Current series, only touches the DSC for DisplayPort. eDP might require
some more changes and also a different policy.

Rev2: Added fix to check that force_dsc_dpc <= connector
max_requested_bpc.

Ankit Nautiyal (3):
  drm/i915/dp: Check if force dsc bpc <= max requested bpc
  drm/i915/dp: Rename helpers to get DSC max pipe bpp and max output bpp
  drm/i915/dp: Get optimal link config to have best compressed bpp

 drivers/gpu/drm/i915/display/intel_dp.c | 229 +++++++++++++++++++-----
 1 file changed, 183 insertions(+), 46 deletions(-)