Enable DSC using the DSC AUX device stored for this purpose in the
connector. For clarity add separate functions to enable/disable the
decompression, since these sequences will diverge more in follow-up
patches that also enable/disable DSC passthrough and on MST do the
actual enabling/disabling only for the first/last user of the given
AUX device. As a preparation for the latter refcounting change, also
pass the atomic state to the functions.
While at it set/clear only the DP_DECOMPRESSION_EN flag in the
DP_DSC_ENABLE DPCD register, preserving the reserved register bits.
Besides preserving the reserved register bits, the behavior stays as
before, as DSC is still only enabled for the first MST stream (which a
follow-up patch changes, enabling it for all streams).
v2:
- Add a helper function setting/clearing the decompression flag,
preserving the reserved register bits.
v3:
- Add separate functions to enable/disable decompression and pass the
atomic state to these.
- Add DocBook for both functions.
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v2)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-24-imre.deak@intel.com
The Synaptics MST hubs expose some sink EDID modes with a reduced HBLANK
period, presumedly to save BW, which the hub expands before forwarding
the stream to the sink. In particular a 4k mode with a standard CVT
HBLANK period is exposed with either a CVT reduced blank RBv1,v2 (80,
160 pixel) or a non-CVT 56 pixel HBLANK period. The DP standard
describes the above HBLANK expansion functionality, but it requires
enabling this explicitly, whereas these hubs apply the expansion
transparently.
In some TBT docks with such a Synaptics hub (DELL WD22TB4) the above modes
will work okay until DSC decompression is enabled in the hub for the given
sink, but after this the same mode will not work reliably in decompressed
mode. In another TBT dock (Thinkpad 40B0) the above modes will not work
in uncompressed/18bpp mode (regardless of whether DSC decompression was
enabled before or not).
As a workaround force enable DSC for such modes. Apply the WA when the
HBLANK period is 300ns or below, matching the above tested modes with a
533.25MHz dotclock and maximum 160 HBLANK pixels.
OTOH DSC for these modes will only work above a certain compressed bpp
threshold which depends on the link rate, so apply this limit as well
in the workaround.
On platforms, pipe/port configurations where DSC is not supported, for
instance on ICL where DSC/MST is still work-in-progress, limit the
minimum link bpp to 24.
Apply the workaround only for Synaptics hubs which support the HBLANK
expansion.
v2:
- Apply the WA whenever the HBLANK period is 300ns or below.
v3:
- Clarify in the commit log the failure modes of the different docks.
- Handle platforms/pipe/port configurations without DSC support.
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v1)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107001505.3370108-4-imre.deak@intel.com
As required by the DP standard wait for the sink to detect the FEC
decode enabling symbol sent by the source.
There is a difference between SST and MST when the source enables
the FEC encoding: on SST this happens only after enabling the
transcoder, whereas on MST it happens already after enabling the
transcoder function (before enabling the transcoder). Wait for the
detected status at the earliest spot accordingly.
v2:
- Wait for the FEC detected status on SST after the transcoder is
enabled.
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-20-imre.deak@intel.com
If an MST stream is modeset, its state must be checked along all the
other streams on the same MST link, for instance to resolve a BW
overallocation of a non-sink MST port or to make sure that the FEC is
enabled/disabled the same way for all these streams.
To prepare for that this patch adds all the stream CRTCs to the atomic
state and marks them for modeset similarly to tgl+ platforms. (If the
state computation doesn't change the state the CRTC is switched back to
fastset mode.)
So far on tgl+ this was required because all streams in the topology
shared the master transcoder. For older platforms this didn't apply but
adding all the state is required now on all platforms based on the
above.
v2:
- Add code and commit log comment clarifying the requirements on old/new
platforms. (Stan)
- Rename the function based on the new semantic. (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-15-imre.deak@intel.com
Atm, the BW allocated for an MST stream doesn't take into account the
DSC control symbol (EOC) and data alignment overhead on the local (first
downstream) MST link (reflected by the data M/N/TU values) and - besides
the above overheads - the FEC symbol overhead on 8b/10b remote
(after a downstream branch device) MST links.
In addition the FEC overhead used on the local link is a fixed amount,
which only applies to certain modes, but not enough for all modes; add a
code comment clarifying this.
Fix the above by calculating the data M/N values with the total BW
overhead (not including the SSC overhead, since this isn't enabled by
the source device) and using this the PBN and TU values for the local
link and PBN for remote links (including SSC, since this is mandatory
for links after downstream branch devices).
For now keep the current fixed FEC overhead as a minimum, since this is
what bspec requires for audio functionality.
Calculate the effective link BW in a clearer way, applying the channel
coding efficiency based on the coding type. The calculation was correct
for 8b/10b, but not for 128b/132b links; this patch leaves the behavior
for this unchanged, leaving the fix for a follow-up.
v2:
- Fix TU size programmed to the HW, making it match the payload size
programmed to the payload table.
v3:
- Add code comment about the connection between the payload's size in
the payload table and the corresponding PBN value. (Ville)
- Add WARN_ON(remote_m_n.tu < dp_m_n.tu). (Ville)
- Add code comment about factors not accounted for by the BW
calculation in intel_dp_mst_mode_valid_ctx() (and compute config).
(Ville)
- Simplify calculation of PBN to remote_m_n.tu * mst_state->pbn_div.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v1)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107001505.3370108-2-imre.deak@intel.com
Enable FEC in crtc_state, as soon as it's known it will be needed by
DSC. This fixes the calculation of BW allocation overhead, in case DSC
is enabled by falling back to it during the encoder compute config
phase (vs. enabling FEC due to DSC being enabled on other streams).
v2:
- Enable FEC only in intel_dp_mst_find_vcpi_slots_for_bpp(), since
only by that will crtc_state->port_clock be set, which in turn is
needed by intel_dp_is_uhbr().
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v1)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-11-imre.deak@intel.com
After drm_connector_init() is called the connector is visible to the
rest of the kernel via the drm_mode_config::connector_list. Make
sure that the DSC AUX device and capabilities are setup by that time.
Another race condition is adding the connector to the connector list
before drm_connector_helper_add() sets the connector helper functions.
That's an unrelated issue, for which the fix is for a follow-up. One
solution would be adding the connector to the connector list only
during its registration in drm_connector_register().
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: 808b43fa7e ("drm/i915/dp_mst: Set connector DSC capabilities and decompression AUX")
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-2-imre.deak@intel.com
The previous patches converted all users of the DSC DPCD caps to look
these up from the connector, so remove the version stored in intel_dp.
A follow-up patchset will read out the MST connector specific
capabilities in intel_dp_add_mst_connector() ->
intel_dp_mst_read_decompression_port_dsc_caps().
v2:
- Rebased on intel_edp_get_dsc_sink_cap() addition in the patchset.
v3:
- Rebased on read-out fix for eDP in the patchset.
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v1)
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/20231011171606.2540078-3-imre.deak@intel.com
Atm the MST encoder config computation may use an out-of-date pbn_div
value, if the sink is unplugged and a sink is replugged with different
link rate/lane count capabilities. The current way of reinitializing
pbn_div depends on pbn_div getting cleared via intel_atomic_check() ->
drm_dp_mst_atomic_check() ->
drm_dp_mst_atomic_check_payload_alloc_limits(), however the clearing
won't happen if the sink got unplugged (and hence
drm_dp_mst_topology_mgr::mst_state being false).
To fix the above, simply update pbn_div unconditionally during config
computation, making pbn_div always match the link rate and lane count.
Cc: Lyude Paul <lyude@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230929154929.343947-1-imre.deak@intel.com
At the moment a modeset fails if the config computation of a pipe can't
fit its required BW to the available link BW even though the limitation
may be resolved by reducing the BW requirement of other pipes.
To improve the above this patch adds helper functions checking the
overall BW limits after all CRTC states have been computed. If the check
fails the maximum link bpp for a selected pipe will be reduced and all
the CRTC states will be recomputed until either the overall BW limit
check passes, or further bpp reduction is not possible (because all
pipes/encoders sharing the link BW reached their minimum link bpp).
Atm, the MST encoder allocates twice the required BW for YUV420 format
streams. A follow-up patchset will fix that, add a code comment about
this.
This change prepares for upcoming patches enabling the above BW
management on FDI and MST links.
v2:
- Rename intel_crtc_state::max_link_bpp to max_link_bpp_x16 and
intel_link_bw_limits::max_bpp to max_bpp_x16. (Jani)
v3:
- Add the helper functions in a separate patch. (Ville)
- Add the functions to intel_link_bw.c instead of intel_atomic.c (Ville)
- Return -ENOSPC instead of -EINVAL to userspace in case of a link BW
limit failure.
v4:
- Make intel_atomic_check_config() static.
v5: (Ville)
- Rename intel_link_bw_limits::min_bpp_pipes to min_bpp_reached_pipes
and intel_link_bw_reset_pipe_limit_to_min() to
intel_link_bw_set_min_bpp_for_pipe().
- Rename pipe_bpp to link_bpp in intel_link_bw_reduce_bpp().
- Add FIXME: comment about MST encoder's YUV420 BW allocation and
tracking the link bpp limit accordingly.
v6:
- Move intel_link_bw_compute_pipe_bpp() to intel_fdi.c (Ville)
- WARN_ON(BIT(pipe) & min_bpp_reached_pipes) in
intel_link_bw_set_bpp_limit_for_pipe(). (Ville)
- Rename intel_link_bw_set_min_bpp_for_pipe() to
intel_link_bw_set_bpp_limit_for_pipe() and
intel_link_bw_limits::min_bpp_reached_pipes to
bpp_limit_reached_pipes. (Ville)
- Remove unused header includes.
Cc: Jani Nikula <jani.nikula@linux.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/20230921195159.2646027-10-imre.deak@intel.com
In non-DSC mode the link bpp can be set in 2*3 bpp steps in the pipe bpp
range, while in DSC mode it can be set in 1/16 bpp steps to any value
up to the maximum pipe bpp. Update the limits accordingly in both modes
to prepare for a follow-up patch which may need to reduce the max link
bpp value and starts to check the link bpp limits in DSC mode as well.
While at it add more detail to the link limit debug print and print it
also for DSC mode.
v2:
- Add to_bpp_frac_dec() instead of open coding it. (Jani)
v3: (Ville)
- Add BPP_X16_FMT / BPP_X16_ARG.
- Add TODO: comment about initializing the DSC link bpp limits earlier.
Cc: Jani Nikula <jani.nikula@linux.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/20230921195159.2646027-5-imre.deak@intel.com
A follow-up patch will need to limit the output link bpp both in the
non-DSC and DSC configuration, so track the pipe and link bpp limits
separately in the link_config_limits struct.
Use .4 fixed point format for link bpp matching the 1/16 bpp granularity
in DSC mode and for now keep this limit matching the pipe bpp limit.
v2: (Jani)
- Add to_bpp_int(), to_bpp_x16() helpers instead of opencoding them.
- Rename link_config_limits::link.min/max_bpp to min/max_bpp_x16.
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@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/20230921195159.2646027-3-imre.deak@intel.com
This reverts commit 959fb1a686.
Looks like the core MST code might not call i2c_adapter() for us
in time, and thus creating the ddc symlink will fail. This will
in fact fail the entire connector registration, but the MST code
doesn't really seem to care about that and blindly plows ahead.
All we may get in the logs is a nearly back to back
register+unregister debug messages:
[drm:drm_dp_mst_connector_late_register [drm_display_helper]] registering DPMST remote bus for card0-DP-7
[drm:intel_dp_hpd_pulse [i915]] DPRX ESI: 42 00 00 02
[drm:drm_dp_mst_connector_early_unregister [drm_display_helper]] unregistering DPMST remote bus for card0-DP-7
Untangling the initialization order may take some real work,
so let's just revert the ddc symlink addition for now...
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9357
Fixes: 959fb1a686 ("drm/i915/mst: Populate connector->ddc")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919095659.10742-1-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Karthik B S <karthik.b.s@intel.com>
[Why]
Today, the allocation/deallocation steps and status is a bit unclear.
For instance, payload->vc_start_slot = -1 stands for "the failure of
updating DPCD payload ID table" and can also represent as "payload is not
allocated yet". These two cases should be handled differently and hence
better to distinguish them for better understanding.
[How]
Define enumeration - ALLOCATION_LOCAL, ALLOCATION_DFP and ALLOCATION_REMOTE
to distinguish different allocation status. Adjust the code to handle
different status accordingly for better understanding the sequence of
payload allocation and payload removement.
For payload creation, the procedure should look like this:
DRM part 1:
* step 1 - update sw mst mgr variables to add a new payload
* step 2 - add payload at immediate DFP DPCD payload table
Driver:
* Add new payload in HW and sync up with DFP by sending ACT
DRM Part 2:
* Send ALLOCATE_PAYLOAD sideband message to allocate bandwidth along the
virtual channel.
And as for payload removement, the procedure should look like this:
DRM part 1:
* step 1 - Send ALLOCATE_PAYLOAD sideband message to release bandwidth
along the virtual channel
* step 2 - Clear payload allocation at immediate DFP DPCD payload table
Driver:
* Remove the payload in HW and sync up with DFP by sending ACT
DRM part 2:
* update sw mst mgr variables to remove the payload
Note that it's fine to fail when communicate with the branch device
connected at immediate downstrean-facing port, but updating variables of
SW mst mgr and HW configuration should be conducted anyway. That's because
it's under commit_tail and we need to complete the HW programming.
Changes since v1:
* Remove the set but not use variable 'old_payload' in function
'nv50_msto_prepare'. Catched by kernel test robot <lkp@intel.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807025639.1612361-3-Wayne.Lin@amd.com
Currently there are many places where we use output_bpp for link bpp and
compressed bpp.
Lets use consistent naming:
output_bpp : The intermediate value taking into account the
output_format chroma subsampling.
compressed_bpp : target bpp for the DSC encoder.
link_bpp : final bpp used in the link.
For 444 sampling without DSC:
link_bpp = output_bpp = pipe_bpp
For 420 sampling without DSC:
output_bpp = pipe_bpp / 2
link_bpp = output_bpp
For 444 sampling with DSC:
output_bpp = pipe_bpp
link_bpp = compressed_bpp, computed with output_bpp (i.e. pipe_bpp in
this case)
For 420 sampling with DSC:
output_bpp = pipe_bpp/2
link_bpp = compressed_bpp, computed with output_bpp
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230817142459.89764-5-ankit.k.nautiyal@intel.com
The decision to use DFP output format conversion capabilities should be
during compute_config phase.
This patch adds new member to crtc_state to represent the final
output_format to the sink. In case of a DFP this can be different than
the output_format, as per the format conversion done via the PCON.
This will help to store only the format conversion capabilities of the
DP device in intel_dp->dfp, and use crtc_state to compute and store the
configuration for color/format conversion for a given mode.
v2: modified the new member to crtc_state to represent the final
output_format that eaches the sink, after possible conversion by
PCON kind of devices. (Ville)
v3: Addressed comments from Ville:
-Added comments to clarify difference between sink_format and
output_format.
-Corrected the order of setting sink_format and output_format.
-Added readout for sink_format in get_pipe_config hooks.
v4: Set sink_format for intel_sdvo too. (Ville)
v5: Rebased.
v6: Fixed condition to go for YCbCr420 format for dp and hdmi. (Ville)
v7: Fix the condition to set sink_format for HDMI.
Set hdmi output_format simply as sink_format. (Ville)
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v3)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230427125605.487769-2-ankit.k.nautiyal@intel.com
