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path: root/drivers/gpu/drm/i915/display/intel_link_bw.c
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2024-02-27drm/i915/dp: Add DP tunnel atomic state and check BW limitImre Deak
Add the atomic state during a modeset required to enable the DP tunnel BW allocation mode on links where such a tunnel was detected. This state applies to an already enabled output, the state added for a newly enabled output will be computed and added/cleared to/from the atomic state in a follow-up patch. v2: - s/old_crtc_state/crtc_state in intel_crtc_duplicate_state(). - Move intel_dp_tunnel_atomic_cleanup_inherited_state() to a follow-up patch adding the corresponding state. (Ville) - Move intel_dp_tunnel_atomic_clear_stream_bw() to a follow-up patch adding the corresponding state. Cc: Ville Syrjälä <ville.syrjala@linux.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/20240220211841.448846-14-imre.deak@intel.com
2024-02-27drm/i915: Fix display bpp limit computation during system resumeImre Deak
The system resume display mode restoration should happen with an output configuration matching that of the suspend time saved mode. Since the restored mode configuration is subject to the bpp fallback logic, starting out with an unlimited bpp and reducing the bpp as required by any (MST) link BW limit, the resulting bpp will match the one during suspend only if the BW limit checks during suspend and resume are applied in an identical way. The latter is not guaranteed at the moment, since the pre-suspend MST topology may not be in place during resume (for instance if the MST sink was disconnected while being suspended), which makes the MST link BW check accept the unlimited bpp mode configuration unconditionally without ensuring that the required BW fits into the available MST link BW. To fix the above, initialize the bpp fallback logic with the max link bpp / force-FEC limits left behind by the suspend time mode save. 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/20240220211841.448846-4-imre.deak@intel.com
2023-11-15drm/i915: Fix fractional bpp handling in intel_link_bw_reduce_bpp()Imre Deak
Convert crtc_state->pipe_bpp to U6.4 format as expected by the rest of the function. Fixes: 59a266f068b4 ("drm/i915/display: Store compressed bpp in U6.4 format") Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com> Cc: Suraj Kandpal <suraj.kandpal@intel.com> Cc: Sui Jingfeng <suijingfeng@loongson.cn> Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20231114141012.603960-1-imre.deak@intel.com
2023-11-14drm/i915/display: Store compressed bpp in U6.4 formatAnkit Nautiyal
DSC parameter bits_per_pixel is stored in U6.4 format. The 4 bits represent the fractional part of the bpp. Currently we use compressed_bpp member of dsc structure to store only the integral part of the bits_per_pixel. To store the full bits_per_pixel along with the fractional part, compressed_bpp is changed to store bpp in U6.4 formats. Intergral part is retrieved by simply right shifting the member compressed_bpp by 4. v2: -Use to_bpp_int, to_bpp_frac_dec, to_bpp_x16 helpers while dealing with compressed bpp. (Suraj) -Fix comment styling. (Suraj) v3: -Add separate file for 6.4 fixed point helper(Jani, Nikula) -Add comment for magic values(Suraj) v4: -Fix checkpatch warnings caused by renaming(Suraj) v5: -Rebase. -Use existing helpers for conversion of bpp_int to bpp_x16 and vice versa. Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com> Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn> Link: https://patchwork.freedesktop.org/patch/msgid/20231110101020.4067342-3-ankit.k.nautiyal@intel.com
2023-11-08drm/i915/dp_mst: Improve BW sharing between MST streamsImre Deak
At the moment modesetting a stream CRTC will fail if the stream's BW along with the current BW of all the other streams on the same MST link is above the total BW of the MST link. Make the BW sharing more dynamic by trying to reduce the link bpp of one or more streams on the MST link in this case. When selecting a stream to reduce the BW for, take into account which link segment in the MST topology ran out of BW and which streams go through this link segment. For instance with A,B,C streams in the same MST topology A and B may share the BW of a link segment downstream of a branch device, stream C not downstream of the branch device, hence not affecting this BW. If this link segment's BW runs out one or both of stream A/B's BW will be reduced until their total BW is within limits. While reducing the link bpp for a given stream DSC may need to be enabled for it, which requires FEC on the whole MST link. Check for this condition and recompute the state for all streams taking the FEC overhead into account (on 8b/10b links). v2: - Rebase on s/min_bpp_pipes/min_bpp_reached_pipes/ change. Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-29-imre.deak@intel.com
2023-09-28drm/i915/fdi: Improve FDI BW sharing between pipe B and CImre Deak
At the moment modesetting pipe C on IVB will fail if pipe B uses 4 FDI lanes. Make the BW sharing more dynamic by trying to reduce pipe B's link bpp in this case, until pipe B uses only up to 2 FDI lanes. For this instead of the encoder compute config retry loop - which reduced link bpp only for the encoder's pipe - reduce the maximum link bpp for pipe B/C as required after all CRTC states are computed and recompute the CRTC states with the new bpp limit. Atm, all FDI encoder's compute config function returns an error if a BW constrain prevents increasing the pipe bpp value. The corresponding crtc_state->bw_constrained check can be replaced with checking crtc_state->max_link_bpp_x16, add TODO comments for this. SDVO is an exception where this case is only handled in the outer config retry loop, failing the modeset with a WARN, add a FIXME comment to handle this in the encoder code similarly to other encoders. v2: - Don't assume that a CRTC is already in the atomic state, while reducing its link bpp. - Add DocBook description to intel_fdi_atomic_check_link(). v3: - Enable BW management for FDI links in a separate patch. (Ville) v4: (Ville) - Fail the SDVO encoder config computation if it doesn't support the link bpp limit. - Add TODO: comments about checking link_bpp_x16 instead of bw_constrained. v5: - Replace link bpp limit check with a FIXME: comment in intel_sdvo_compute_config(). (Ville) Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> [Amended commit message wrt. changes in v5] Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230921195159.2646027-11-imre.deak@intel.com
2023-09-28drm/i915: Add helpers for BW management on shared display linksImre Deak
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