drm/amd/display: Linux set/read lane settings through debugfs
function: get current DP PHY settings: voltage swing, pre-emphasis,
post-cursor2 (defined by VESA DP specification)
valid values: voltage swing: 0,1,2,3 pre-emphasis : 0,1,2,3
post cursor2 : 0,1,2,3
debugfs file phy_setings is located at /sys/kernel/debug/dri/0/DP-x
there will be directories, like DP-1, DP-2,DP-3, etc. for DP display
--- to figure out which DP-x is the display for DP to be check,
cd DP-x
ls -ll
There should be debugfs file, like link_settings, phy_settings.
cat link_settings
from lane_count, link_rate to figure which DP-x is for display to be
worked on
--- to get current DP PHY settings,
cat phy_settings