Hours Of Battery Life is a new GEN12+ power-saving feature that allows
supported motherboards to use a special voltage swing table for eDP
panels that uses less power.
So here if supported by HW, OEM will set it in VBT and i915 will try
to train link with HOBL vswing table if link training fails it fall
back to the original table.
intel_ddi_dp_preemph_max() was optimized to only check the HOBL flag
instead of do something like is done in intel_ddi_dp_voltage_max()
because it is only called after the first entry of the voltage swing
table was loaded so the HOBL flag is valid at that point.
v3:
- removed a few parameters of icl_ddi_combo_vswing_program() that
can be taken from encoder
v4:
- using the HOBL vswing table until training fails completely (Ville)
v5:
- not reducing lane or link rate when link training fails with HOBL
active
- duplicated the HOBL voltage swing entry to match DP spec requirement
v6:
- removed the optional VS 3 & pre-emp 0 from HOBL table
- changed from u8:1 to bool to store hobl_failed/active
BSpec: 49291
BSpec: 49399
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200715175637.33763-1-jose.souza@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
The DP spec says:
"The transmitter shall support at least three levels of voltage
swing (Levels 0, 1, and 2).
If only three levels of voltage swing are supported (VOLTAGE
SWING SET field (bits 1:0) are programmed to 10 (Level 2)),
this bit shall be set to 1, and cleared in all other cases.
If all four levels of voltage swing are supported (VOLTAGE
SWING SET field (bits 1:0) are programmed to 11 (Level 3)),
this bit shall be set to 1,and cleared in all other cases."
Let's follow that exactly instead of the current apporach
where we can set those also for vswing/preemph levels 0 or 1
(or 2 when the platform max is 3).
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-7-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
The DP spec says:
"When the combination of the requested pre-emphasis level and
voltage swing exceeds the capability of a DPTX, the DPTX shall
set the pre-emphasis level according to the request and use the
highest voltage swing it can output with the given pre-emphasis level."
and
"When a DPTX reads a request beyond the limits of this Standard,
the DPTX shall set the pre-emphasis level according to the request
and set the highest voltage swing level it can output with the
given pre-emphasis level. If a DPTX is requested for 9.5dB of
pre-emphasis level (may be supported for a DPTX) and cannot support
that level, it shall set the pre-emphasis level to the next
highest level, 6dB."
Ie. we should first validate the pre-emphasis, and then select
the appropriate vswing for it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-6-ville.syrjala@linux.intel.com
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
vswing/pre-emphasis adjustment calculation is needed in processing
of auto phy compliance request other than link training, so have
made non-static function.
No functional change.
v1: initial patch.
v2:
- used "intel_dp" prefix in function name. (Jani)
- used array notation instead pointer for link_status. (Ville)
v3: Scrapped the initial patch, modified commit description accordingly.
- made non-static function and used intel_dp prefix. (Jani, Manasi)
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200316103759.12867-4-animesh.manna@intel.com
