At the end of a 128b/132b link training sequence, the HW expects the
transcoder training pattern to be set to TPS2 and from that to normal
mode (disabling the training pattern). Transitioning from TPS1 directly
to normal mode leaves the transcoder in a stuck state, resulting in
page-flip timeouts later in the modeset sequence.
Atm, in case of a failure during link training, the transcoder may be
still set to output the TPS1 pattern. Later the transcoder is then set
from TPS1 directly to normal mode in intel_dp_stop_link_train(), leading
to modeset failures later as described above. Fix this by setting the
training patter to TPS2, if the link training failed at any point.
The clue in the specification about the above HW behavior is the
explicit mention that TPS2 must be set after the link training sequence
(and there isn't a similar requirement specified for the 8b/10b link
training), see the Bspec links below.
v2: Add bspec aspect/link to the commit log. (Jani)
Bspec: 54128, 65448, 68849
Cc: stable@vger.kernel.org # v5.18+
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250217223828.1166093-2-imre.deak@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 8b4bbaf8dd)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Use a forward declaration for struct cec_notifier instead of including
media/cec-notifier.h in intel_display_types.h, and only include it where
needed.
Also realize that a lot of places depend on including linux/debugfs.h
via intel_display_types.h -> media/cec-notifier.h -> media/cec.h, and
include that too where needed.
v2: hsw_ips.c also needs debugfs.h (kernel test robot)
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240827104521.4151471-1-jani.nikula@intel.com
On MST links - at least for some MST branch devices - the list of modes
returned to users on an enabled link depends on the current link
rate/lane count parameters (besides the DPRX link capabilities, any MST
branch BW limit and the maximum link parameters reduced after LT
failures). In particular the MST branch BW limit may depend on the link
rate/lane count parameters programmed to DPCD. After an LT failure and
limiting the maximum link parameters accordingly, users should see a
mode list reflecting these new limits. However with the current fallback
order this isn't ensured, as the new limit could allow for modes
requiring a higher link BW, but these modes will be filtered out due to
the enabled link's lower link BW.
Ensure that the mode list changes in a consistent way after a link
training failure and reducing the link parameters by changing the
fallback order on MST links to happen in BW order.
v2:
- s/INTEL_DP_MAX_SUPPORTED_LANE_COUNTS/INTEL_DP_MAX_SUPPORTED_LANE_CONFIGS
and s/num_common_lane_counts/num_common_lane_configs to make the
difference wrt. max lane counts clearer. (Suraj)
- Add a TODO comment to make the SST fallback logic work the same way as
MST. (Arun)
- Use sort_r()'s default swap function instead of a custom one.
Cc: Suraj Kandpal <suraj.kandpal@intel.com>
Cc: Arun R Murthy <arun.r.murthy@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240729144458.2763667-1-imre.deak@intel.com
Add connector debugfs entries to force the link rate/lane count to be
used by a link training afterwards. These settings will be clamped to
the supported, i.e. the source's and sink's common rate/lane count.
After forcing the link rate/lane count reset the link training
parameters and for a non-auto setting disable reducing the link
parameters via the fallback logic. The former one can be used after
testing link training failure scenarios - via debugfs entries added
later - to reset the reduced link parameters after the test.
v2:
- Add the entries from intel_dp_link_training.c (Jani)
- Rename the entries to i915_dp_set_link_rate/lane_count.
v3: (Ville)
- Rename the entries/struct fields to force_link_rate/lane_count.
- Lock connection_mutex only for the required intel_dp state.
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-18-imre.deak@intel.com
After a link training failure if the link parameters can't be further
reduced, there is no point in trying to retrain the link in the driver.
This avoids excessive retrain attempts after detecting a bad link, for
instance while handling MST HPD IRQs, which is likely redundant as the
link training failed already twice with the same minimum link
parameters. Userspace can still try to retrain the link with these
parameters via a modeset.
While at it make the error message more accurate.
v2: Move converting the error to a debug message to the relevant
follow-up patch. (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-15-imre.deak@intel.com
The next patch adds sending a modeset-retry uevent after a link training
failure to all MST connectors on link. This requires the atomic state,
so pass it to intel_dp_start_link_train(). In case of SST where
retraining still happens by calling this function directly instead of a
modeset commit the atomic state is not available and NULL is passed
instead. This is ok, since in this case the encoder's only DP connector
is available from intel_dp->attached_connector not requiring the atomic
state.
v2: Add NOTE that the atomic state may not be valid for SST links and
assert that it's valid for MST links. (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-10-imre.deak@intel.com
Recheck the link state after a passing link training, with a 2 sec delay
to account for cases where the link goes bad following the link training
and the sink doesn't report this via an HPD IRQ.
The delayed work added here will be also used by a later patch after a
failed link training to try to retrain the link with unchanged link
params before reducing the link params.
v2: Don't flush an uninitialized delayed work (on HDMI-only DDI ports).
v3:
- Move the helpers to a new intel_encoder.c file, rename them
accordingly. (Ville)
- Add the work to intel_encoder instead of intel_digital_port.
- Call the encoder specific link check function via an encoder hook.
- Flush the link check work during encoder destroy from
intel_dp_encoder_flush_work().
- Flush the link check work during encoder suspend as well.
v4: Call intel_encoder_link_check_init() with a valid encoder pointer.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610181428.2955658-1-imre.deak@intel.com
Reduce the indentation in intel_dp_get_link_train_fallback_values() by
adding separate helpers to reduce the link rate and lane count. Also
simplify things by passing crtc_state to the function.
This also prepares for later patches in the patchset adding a limitation
on how the link params are reduced.
While at it use lt_dbg()/lt_err() for debug/error prints in the function
which will also print the connector/encoder prefix and add a debug print
about reducing the link parameters.
v2:
- Align reduce_lane_count()'s error handling flow with
reduce_link_rate(). (Ville, Jani)
- Use lt_dbg()/lt_err() in the function.
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-5-imre.deak@intel.com
On shared (Thunderbolt) links with DP tunnels, the modeset may need to
be retried on all connectors on the link due to a link BW limitation
arising only after the atomic check phase. To support this add a helper
function queuing a work to retry the modeset on a given port's connector
and at the same time any MST connector with streams through the same
port. A follow-up change enabling the DP tunnel Bandwidth Allocation
Mode will take this into use.
v2:
- Send the uevent only to enabled MST connectors. (Jouni)
Cc: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-5-imre.deak@intel.com
Move VRR enabling/disabling into a place where it also works
for fastsets.
With this we always start the transcoder up in non-VRR mode.
Granted we already did that but for a very short period of
time. But now that we might end up doing a bit more with the
transcoder in non-VRR mode it seems prudent to also update
the active timings as the transcoder changes its operating
mode.
crtc_state->vrr.enable still tracks whether VRR is actually
enabled or not, but now we configure all the other VRR timing
registers whenever VRR is possible (whether we actually enable
it or not). crtc_state->vrr.flipline can now serve as our
"is VRR possible" bit of state.
I decided to leave the MSA timing ignore bit set all the time
whether VRR is actually enabled or not. If the sink can figure
out the timings with that information when VRR is active then
surely it can also do it when VRR is inactive.
v2: Protect intel_vrr_set_transcoder_timings() with HAS_VRR()
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230321135615.27338-1-ville.syrjala@linux.intel.com
Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Enable SDP error detection configuration, this will set CRC16 in
128b/132b link layer.
For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is
added to enable/disable SDP CRC applicable for DP2.0 only, but the
default value of this bit will enable CRC16 in 128b/132b hence
skipping this write.
Corrective actions on SDP corruption is yet to be defined.
v2: Moved the CRC enable to link training init(Jani N)
v3: Moved crc enable to ddi pre enable <Jani N>
v4: Separate function for SDP CRC16 (Jani N)
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302081532.765821-3-arun.r.murthy@intel.com
A lot of modern laptops use the Parade PS8461E MUX for eDP
switching. The MUX can operate in jitter cleaning mode or
redriver mode, the first one resulting in higher link
quality. The jitter cleaning mode needs to know the link
rate used and the MUX achieves this by snooping the
LINK_BW_SET, LINK_RATE_SELECT and SUPPORTED_LINK_RATES
DPCD accesses.
When the MUX is powered down (seems this can happen whenever
the display is turned off) it loses track of the snooped
link rates so when we do the LINK_RATE_SELECT write it no
longer knowns which link rate we're selecting, and thus it
falls back to the lower quality redriver mode. This results
in unstable high link rates (eg. usually 8.1Gbps link rate
no longer works correctly).
In order to avoid all that let's re-snoop SUPPORTED_LINK_RATES
from the sink at the start of every link training.
Unfortunately we don't have a way to detect the presence of
the MUX. It looks like the set of laptops equipped with this
MUX is fairly large and contains devices from multiple
manufacturers. It may also still be growing with new models.
So a quirk doesn't seem like a very easily maintainable
option, thus we shall attempt to do this unconditionally on
all machines that use LINK_RATE_SELECT. Hopefully this extra
DPCD read doesn't cause issues for any unaffected machine.
If that turns out to be the case we'll need to convert this
into a quirk in the future.
Cc: stable@vger.kernel.org
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6205
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220902070319.15395-1-ville.syrjala@linux.intel.com
Tested-by: Aaron Ma <aaron.ma@canonical.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
