Hersen Wu 41db5f1931 drm/amd/display: set-read link rate and lane count through debugfs ... function description get/ set DP configuration: lane_count, link_rate, spread_spectrum valid lane count value: 1, 2, 4 valid link rate value: 06h = 1.62Gbps per lane 0Ah = 2.7Gbps per lane 0Ch = 3.24Gbps per lane 14h = 5.4Gbps per lane 1Eh = 8.1Gbps per lane debugfs is located at /sys/kernel/debug/dri/0/DP-x/link_settings --- to get dp configuration xxd -l 300 phy_settings It will list current, verified, reported, preferred dp configuration. current -- for current video mode verified --- maximum configuration which pass link training reported --- DP rx report caps (DPCD register offset 0, 1 2) preferred --- user force settings --- set (or force) dp configuration echo <lane_count> <link_rate> for example, to force to 2 lane, 2.7GHz, echo 4 0xa > link_settings spread_spectrum could not be changed dynamically. in case invalid lane count, link rate are force, no hw programming will be done. please check link settings after force operation to see if HW get programming. xxd -l 300 link_settings check current and preferred settings. Signed-off-by: Hersen Wu <hersenxs.wu@amd.com> Reviewed-by: Hersen Wu <hersenxs.wu@amd.com> Acked-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>		2018-07-13 14:47:45 -05:00
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drm	drm/amd/display: set-read link rate and lane count through debugfs	2018-07-13 14:47:45 -05:00
host1x	drm for v4.18-rc1	2018-06-06 08:16:33 -07:00
ipu-v3
vga	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
Makefile