The driver currently disables the LTTPR non-transparent link training
mode for sinks with a DPCD_REV<1.4, based on the following description
of the LTTPR DPCD register range in DP standard 2.0 (at the 0xF0000
register description):

""
LTTPR-related registers at DPCD Addresses F0000h through F02FFh are valid
only for DPCD r1.4 (or higher).
"""

The transparent link training mode should still work fine, however the
implementation for this in some retimer FWs seems to be broken, see the
References: link below.

After discussions with DP standard authors the above "DPCD r1.4" does
not refer to the DPCD revision (stored in the DPCD_REV reg at 0x00000),
rather to the "LTTPR field data structure revision" stored in the
0xF0000 reg. An update request has been filed at vesa.org (see
wg/Link/documentComment/3746) for the upcoming v2.1 specification to
clarify the above description along the following lines:

"""
LTTPR-related registers at DPCD Addresses F0000h through F02FFh are
valid only for LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV 1.4 (or
higher)
"""

Based on my tests Windows uses the non-transparent link training mode
for DPCD_REV==1.2 sinks as well (so presumably for all DPCD_REVs), and
forcing it to use transparent mode on ICL/TGL platforms leads to the
same LT failure as reported at the References: link.

Based on the above let's assume that the transparent link training mode
is not well tested/supported and align the code to the correct
interpretation of what the r1.4 version refers to.
Reported-and-tested-by: NCasey Harkins <caseyharkins@gmail.com>
Tested-by: NKhaled Almahallawy <khaled.almahallawy@intel.com>
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3415
Fixes: 264613b4 ("drm/i915: Disable LTTPR support when the DPCD rev < 1.4")
Cc: <stable@vger.kernel.org> # v5.11+
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NKhaled Almahallawy <khaled.almahallawy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210512212809.1234701-1-imre.deak@intel.com

The glk display version change is causing us to again attempt
LTTPR detection on glk. We must not do tha since glk doesn't
have a long enough AUX timeout. Restore the correct logic to
skip the detection.

Cc: Matt Roper <matthew.d.roper@intel.com>
Fixes: 2b5a4562 ("drm/i915/display: Simplify GLK display version tests")
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412054607.18133-4-ville.syrjala@linux.intel.com
(cherry picked from commit 543d592a)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

In case AUX failures happen unexpectedly during a modeset, the driver
should still complete the modeset. In particular the driver should
perform the link training sequence steps even in case of an AUX failure,
as this sequence also includes port initialization steps. Not doing that
can leave the port/pipe in a broken state and lead for instance to a
flip done timeout.

Fix this by continuing with link training (in a no-LTTPR mode) if the
DPRX DPCD readout failed for some reason at the beginning of link
training. After a successful connector detection we already have the
DPCD read out and cached, so the failed repeated read for it should not
cause a problem. Note that a partial AUX read could in theory partly
overwrite the cached DPCD (and return error) but this overwrite should
not happen if the returned values are corrupted (due to a timeout or
some other IO error).

Kudos to Ville to root cause the problem.

Fixes: 7dffbded ("drm/i915: Disable LTTPR support when the DPCD rev < 1.4")
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3308
Cc: stable@vger.kernel.org # 5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412232413.2755054-1-imre.deak@intel.com
(cherry picked from commit e42e7e58)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
[adjusted Fixes: tag]

The address-of op in front of an array is just an alias to using the
array on its own, so drop the op.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412232413.2755054-2-imre.deak@intel.com

In case AUX failures happen unexpectedly during a modeset, the driver
should still complete the modeset. In particular the driver should
perform the link training sequence steps even in case of an AUX failure,
as this sequence also includes port initialization steps. Not doing that
can leave the port/pipe in a broken state and lead for instance to a
flip done timeout.

Fix this by continuing with link training (in a no-LTTPR mode) if the
DPRX DPCD readout failed for some reason at the beginning of link
training. After a successful connector detection we already have the
DPCD read out and cached, so the failed repeated read for it should not
cause a problem. Note that a partial AUX read could in theory partly
overwrite the cached DPCD (and return error) but this overwrite should
not happen if the returned values are corrupted (due to a timeout or
some other IO error).

Kudos to Ville to root cause the problem.

Fixes: 264613b4 ("drm/i915: Disable LTTPR support when the DPCD rev < 1.4")
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3308
Cc: stable@vger.kernel.org # 5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412232413.2755054-1-imre.deak@intel.com

The glk display version change is causing us to again attempt
LTTPR detection on glk. We must not do tha since glk doesn't
have a long enough AUX timeout. Restore the correct logic to
skip the detection.

Cc: Matt Roper <matthew.d.roper@intel.com>
Fixes: 2b5a4562 ("drm/i915/display: Simplify GLK display version tests")
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412054607.18133-4-ville.syrjala@linux.intel.com

Use Coccinelle to convert most of the usage of INTEL_GEN() and IS_GEN()
in the display code to use DISPLAY_VER() comparisons instead.  The
following semantic patch was used:

        @@ expression dev_priv, E; @@
        - INTEL_GEN(dev_priv) == E
        + IS_DISPLAY_VER(dev_priv, E)

        @@ expression dev_priv; @@
        - INTEL_GEN(dev_priv)
        + DISPLAY_VER(dev_priv)

        @@ expression dev_priv; expression E; @@
        - IS_GEN(dev_priv, E)
        + IS_DISPLAY_VER(dev_priv, E)

        @@
        expression dev_priv;
        expression from, until;
        @@
        - IS_GEN_RANGE(dev_priv, from, until)
        + IS_DISPLAY_RANGE(dev_priv, from, until)

There are still some display-related uses of INTEL_GEN() in intel_pm.c
(watermark code) and i915_irq.c.  Those will be updated separately.

v2:
 - Use new IS_DISPLAY_RANGE and IS_DISPLAY_VER helpers.  (Jani)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NLucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210320044245.3920043-4-matthew.d.roper@intel.com

By the specification the 0xF0000 - 0xF02FF range is only valid if the
LTTPR revision at 0xF0000 is at least 1.4. Disable the LTTPR support
otherwise.

Fixes: 7b2a4ab8 ("drm/i915: Switch to LTTPR transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317184901.4029798-4-imre.deak@intel.com
(cherry picked from commit 1663ad49)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

By the specification the 0xF0000-0xF02FF range is only valid when the
DPCD revision is 1.4 or higher. Disable LTTPR support if this isn't so.

Trying to detect LTTPRs returned corrupted values for the above DPCD
range at least on a Skylake host with an LG 43UD79-B monitor with a DPCD
revision 1.2 connected.

v2: Add the actual version check.
v3: Fix s/DRPX/DPRX/ typo.

Fixes: 7b2a4ab8 ("drm/i915: Switch to LTTPR transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317190149.4032966-1-imre.deak@intel.com
(cherry picked from commit 264613b4)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

The spec requires to use at least 3.2ms for the AUX timeout period if
there are LT-tunable PHY Repeaters on the link (2.11.2). An upcoming
spec update makes this more specific, by requiring a 3.2ms minimum
timeout period for the LTTPR detection reading the 0xF0000-0xF0007
range (3.6.5.1).

Accordingly disable LTTPR detection until GLK, where the maximum timeout
we can set is only 1.6ms.

Link training in the non-transparent mode is known to fail at least on
some SKL systems with a WD19 dock on the link, which exposes an LTTPR
(see the References below). While this could have different reasons
besides the too short AUX timeout used, not detecting LTTPRs (and so not
using the non-transparent LT mode) fixes link training on these systems.

While at it add a code comment about the platform specific maximum
timeout values.

v2: Add a comment about the g4x maximum timeout as well. (Ville)
Reported-by: NTakashi Iwai <tiwai@suse.de>
Reported-and-tested-by: NSantiago Zarate <santiago.zarate@suse.com>
Reported-and-tested-by: NBodo Graumann <mail@bodograumann.de>
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3166
Fixes: b30edfd8 ("drm/i915: Switch to LTTPR non-transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317184901.4029798-2-imre.deak@intel.com
(cherry picked from commit 984982f3)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

intel_dp_program_link_training_pattern() clearly belongs in
intel_dp_link_training.c. Make it so.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210318161015.22070-4-ville.syrjala@linux.intel.com

By the specification the 0xF0000 - 0xF02FF range is only valid if the
LTTPR revision at 0xF0000 is at least 1.4. Disable the LTTPR support
otherwise.

Fixes: 7b2a4ab8 ("drm/i915: Switch to LTTPR transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317184901.4029798-4-imre.deak@intel.com

By the specification the 0xF0000-0xF02FF range is only valid when the
DPCD revision is 1.4 or higher. Disable LTTPR support if this isn't so.

Trying to detect LTTPRs returned corrupted values for the above DPCD
range at least on a Skylake host with an LG 43UD79-B monitor with a DPCD
revision 1.2 connected.

v2: Add the actual version check.
v3: Fix s/DRPX/DPRX/ typo.

Fixes: 7b2a4ab8 ("drm/i915: Switch to LTTPR transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317190149.4032966-1-imre.deak@intel.com

The spec requires to use at least 3.2ms for the AUX timeout period if
there are LT-tunable PHY Repeaters on the link (2.11.2). An upcoming
spec update makes this more specific, by requiring a 3.2ms minimum
timeout period for the LTTPR detection reading the 0xF0000-0xF0007
range (3.6.5.1).

Accordingly disable LTTPR detection until GLK, where the maximum timeout
we can set is only 1.6ms.

Link training in the non-transparent mode is known to fail at least on
some SKL systems with a WD19 dock on the link, which exposes an LTTPR
(see the References below). While this could have different reasons
besides the too short AUX timeout used, not detecting LTTPRs (and so not
using the non-transparent LT mode) fixes link training on these systems.

While at it add a code comment about the platform specific maximum
timeout values.

v2: Add a comment about the g4x maximum timeout as well. (Ville)
Reported-by: NTakashi Iwai <tiwai@suse.de>
Reported-and-tested-by: NSantiago Zarate <santiago.zarate@suse.com>
Reported-and-tested-by: NBodo Graumann <mail@bodograumann.de>
References: https://gitlab.freedesktop.org/drm/intel/-/issues/3166
Fixes: b30edfd8 ("drm/i915: Switch to LTTPR non-transparent mode link training")
Cc: <stable@vger.kernel.org> # v5.11
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210317184901.4029798-2-imre.deak@intel.com

One instance of DRM_DEBUG_KMS was leftover in dp_link_training, convert
it to the new shiny.
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210310214845.29021-2-sean@poorly.run

This patch adds some newlines which are missing from debug messages.
This will prevent logs from being stacked up in dmesg.
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210310214845.29021-1-sean@poorly.run

The DP PHY vswing/pre-emphasis level programming the driver does is
related to the DPTX -> first LTTPR link segment only. Accordingly it
should be only programmed when link training the first LTTPR and kept
as-is when training subsequent LTTPRs and the DPRX. For these latter
PHYs the vs/pe levels will be set in response to writing the
DP_TRAINING_LANEx_SET_PHY_REPEATERy DPCD registers (by an upstream LTTPR
TX PHY snooping this write access of its downstream LTTPR/DPRX RX PHY).
The above is also described in DP Standard v2.0 under 3.6.6.1.

While at it simplify and add the LTTPR that is link trained to the debug
message in intel_dp_set_signal_levels().

Fixes: b30edfd8 ("drm/i915: Switch to LTTPR non-transparent mode link training")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201229172201.4155327-2-imre.deak@intel.com
(cherry picked from commit 67fba3f1)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

intel_dp_set_signal_levels() is needed for link training, so move it to
intel_dp_link_training.c.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201229172201.4155327-1-imre.deak@intel.com
(cherry picked from commit 1c6e527d)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Atm, the driver programs explicitly the default transparent link
training mode (0x55) to DP_PHY_REPEATER_MODE even if no LTTPRs are
detected.

This conforms to the spec (3.6.6.1):
"DP upstream devices that do not enable the Non-transparent mode of
 LTTPRs shall program the PHY_REPEATER_MODE register (DPCD Address
 F0003h) to 55h (default) prior to link training"

however writing the default value to this DPCD register seems to cause
occasional link training errors at least for a DELL WD19TB TBT dock, when
no LTTPRs are detected.

Writing to DP_PHY_REPEATER_MODE will also cause an unnecessary timeout
on systems without any LTTPR.

To fix the above two issues let's assume that setting the default mode
is redundant when no LTTPRs are detected. Keep the existing behavior and
program the default mode if more than 8 LTTPRs are detected or in case
the read from DP_PHY_REPEATER_CNT returns an invalid value.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/2801Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NKhaled Almahallawy <khaled.almahallawy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210118183143.1145707-1-imre.deak@intel.com

If VRR is enabled, the sink should ignore MSA parameters
and regenerate incoming video stream without depending
on these parameters. Hence set the MSA_TIMING_PAR_IGNORE_EN
bit if VRR is enabled.
Reset this bit on VRR disable.

v2:
* ACtually set the dpcd msa ignore bit (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122232647.22688-13-manasi.d.navare@intel.com

DP spec says:
"The Source device shall start sending the idle pattern after
 it has cleared the Training_Pattern byte in the DPCD."

Currently we do these in operations in the opposite order.
Swap them around to match the spec.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210118162107.18424-1-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

The DP PHY vswing/pre-emphasis level programming the driver does is
related to the DPTX -> first LTTPR link segment only. Accordingly it
should be only programmed when link training the first LTTPR and kept
as-is when training subsequent LTTPRs and the DPRX. For these latter
PHYs the vs/pe levels will be set in response to writing the
DP_TRAINING_LANEx_SET_PHY_REPEATERy DPCD registers (by an upstream LTTPR
TX PHY snooping this write access of its downstream LTTPR/DPRX RX PHY).
The above is also described in DP Standard v2.0 under 3.6.6.1.

While at it simplify and add the LTTPR that is link trained to the debug
message in intel_dp_set_signal_levels().

Fixes: b30edfd8 ("drm/i915: Switch to LTTPR non-transparent mode link training")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201229172201.4155327-2-imre.deak@intel.com

intel_dp_set_signal_levels() is needed for link training, so move it to
intel_dp_link_training.c.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201229172201.4155327-1-imre.deak@intel.com

The DP Standard's recommendation is to use the LTTPR non-transparent
mode link training if LTTPRs are detected, so let's do this.

Besides power-saving, the advantages of this are that the maximum number
of LTTPRs can only be used in non-transparent mode (the limit is 5-8 in
transparent mode), and it provides a way to narrow down the reason for a
link training failure to a given link segment. Non-transparent mode is
probably also the mode that was tested the most by the industry.

The changes in this patchset:
- Pass the DP PHY that is currently link trained to all LT helpers, so
  that these can access the correct LTTPR/DPRX DPCD registers.
- During LT take into account the LTTPR common lane rate/count and the
  per LTTPR-PHY vswing/pre-emph limits.
- Switch to LTTPR non-transparent LT mode and train each link segment
  according to the sequence in DP Standard v2.0 (complete CR/EQ for
  each segment before continuing with the next segment).

v2:
- Switch to non-transparent mode during connector detection, which is
  required before reading the per-PHY LTTPR capabilities.
- Move the DP_PHY_LTTPR() macro to drm_dp_helper.h (Ville)
- Use the new drm_dp_dpcd_read_phy_link_status() instead of adding the
  same logic to intel_dp_get_link_status(). (Ville)
- Make intel_dp_lttpr_phy_caps() return a pointer to the whole array
  instead of a pointer to its first element. (Ville)
- Add the intel_dp_phy_is_downstream_of_source() helper. (Ville)
- Add a code comment about the disable->enable quirk of
  non-transparent mode.
- Add the intel_dp_training_pattern_set_reg() helper.
- Fix checkpatch/sparse warns.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-7-imre.deak@intel.com

By default LTTPRs should be in transparent link training mode,
nevertheless in this patch we switch to this default mode explicitly.

The DP Standard recommends this, supposedly because an LTTPR may be left
in the non-transparent mode (by BIOS, previous kernel, or after reset
due to a firmware bug). I haven't seen this happening, but let's follow
the DP Standard.

v2:
- Add a code comment about the explicit disabling of non-transparent
  mode.
v3:
- Move check to prevent initing LTTPRs on eDP to init_dp_lttpr_init().

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-6-imre.deak@intel.com

To prepare for a follow-up LTTPR change factor out a helper to disable
the training pattern in DPCD. We'll need to do this for each LTTPR
(without programming the port to output the idle pattern) when training
in LTTPR non-transparent mode.

While at it also move the disable-link-training logic from
intel_dp_set_link_train() to intel_dp_stop_link_train(), since the
latter is the only user of this.

v2:
- Move the disable-link-training logic to intel_dp_stop_link_train()
  (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-4-imre.deak@intel.com

Split the prepare, link training, fallback-handling steps into their own
functions for clarity and as a preparation for the upcoming LTTPR
changes.

While at it also:
- Unexport and inline intel_dp_set_idle_link_train(), which is used at a
  single place.
- Add some documentation to functions that are exported or that can use
  a better description about which part of the LT sequence they
  implement.

v2: (Ville)
- Unexport/inline intel_dp_set_idle_link_train()
- Make the documentation of
  intel_dp_prepare_link_train()/intel_dp_stop_link_train() more accurate
  wrt. HW specific details.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-3-imre.deak@intel.com

An LTTPR can be trained with training pattern 4 even if the DPCD
revision is < 1.4, but drm_dp_training_pattern_mask() would change
pattern 4 to pattern 3 on those DPCD revisions.

Since intel_dp_training_pattern() makes already sure that the proper
training pattern is used, all that needs to be masked out is the
scrambling disable flag, which is or'd to the mask later based on the
training pattern.

v2:
- Use a helper instead of open-coding the masking. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201007170917.1764556-2-imre.deak@intel.com

Get rid of mode crtc->config usage, and some ad-hoc intel_dp state
usage by plumbing the crtc state all the way down to the link training
code.

Unfortunately we do have to keep some cached state in intel_dp so
that we can do the "does the link need retraining?" checks from
the short hpd handler.

v2: Add intel_crtc_state forward declaration
v3: Don't kill the PHY test code totally since it's
    now in the hotplug work where we can get at the states
v4: Don't resurrect the debug scrambling disable bit (Imre)
    Use intel_dp_mst_is_master_trans() (Imre)
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201001111053.24451-1-ville.syrjala@linux.intel.com

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: NVille 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: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200715175637.33763-1-jose.souza@intel.comSigned-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

According to the DP spec a DPTX must support vswing/pre-emphasis
up to and including level 2. Level 3 is optional (actually DP 1.4a
seems to make even level 3 mandatory for HBR2/3, while leaving it
optional for RBR/HBR1).

WARN if out encoders' .voltage_max()/.preemph_max() return
an illegal value.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200709145845.18118-1-ville.syrjala@linux.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: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-7-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Use max() instead of hand rolling it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-8-ville.syrjala@linux.intel.comReviewed-by: NManasi Navare <manasi.d.navare@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: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-6-ville.syrjala@linux.intel.comReviewed-by: NManasi Navare <manasi.d.navare@intel.com>

Different platforms have different max vswing/preemph settings.
Turn that into a pair vfuncs so we can decouple intel_dp.c and
intel_ddi.c further.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-5-ville.syrjala@linux.intel.comReviewed-by: NManasi 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: NManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200316103759.12867-4-animesh.manna@intel.com

Converts various instances of the printk based drm logging macros to the
struct drm_device based logging macros in
i915/display/intel_dp_link_training.c.
This also involves extracting the drm_i915_private device pointer from
the intel_dp type to use in the various macros.
Signed-off-by: NWambui Karuga <wambui.karugax@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200206080014.13759-3-wambui.karugax@gmail.com

Everything about the file is about display, and mostly about types
related to display. Move under display/ as intel_display_types.h to
reflect the facts.

There's still plenty to clean up, but start off with moving the file
where it logically belongs and naming according to contents.

v2: fix the include guard name in the renamed file
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806113933.11799-1-jani.nikula@intel.com

Add a new subdirectory for display code, and start off by moving
modesetting output/encoder code. Judging by the include changes, this is
a surprisingly clean operation.

v2:
- move intel_sdvo_regs.h too
- use tabs for Makefile	file lists and sort them

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613084416.6794-2-jani.nikula@intel.com

It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.

Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.

No functional changes.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/eb23be64d04957b2cf82b79fd69cc57ed84043a4.1556540889.git.jani.nikula@intel.com