8ca0b875c0
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
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.