91888b5b1a
Add support to enable the DP tunnel BW allocation mode. Follow-up patches will call the required helpers added here to prepare for a modeset on a link with DP tunnels, the last change in the patchset actually enabling BWA. With BWA enabled, the driver will expose the full mode list a display supports, regardless of any BW limitation on a shared (Thunderbolt) link. Such BW limits will be checked against only during a modeset, when the driver has the full knowledge of each display's BW requirement. If the link BW changes in a way that a connector's modelist may also change, userspace will get a hotplug notification for all the connectors sharing the same link (so it can adjust the mode used for a display). The BW limitation can change at any point, asynchronously to modesets on a given connector, so a modeset can fail even though the atomic check for it passed. In such scenarios userspace will get a bad link notification and in response is supposed to retry the modeset. v2: - Fix old vs. new connector state in intel_dp_tunnel_atomic_check_state(). (Ville) - Fix propagating the error from intel_dp_tunnel_atomic_compute_stream_bw(). (Ville) - Move tunnel==NULL checks from driver to DRM core helpers. (Ville) - Simplify return flow from intel_dp_tunnel_detect(). (Ville) - s/dp_tunnel_state/inherited_dp_tunnels (Ville) - Simplify struct intel_dp_tunnel_inherited_state. (Ville) - Unconstify object pointers (vs. states) where possible. (Ville) - Init crtc_state while declaring it in check_group_state(). (Ville) - Join obj->base.id, obj->name arg lines in debug prints to reduce LOC. (Ville) - Add/rework intel_dp_tunnel_atomic_alloc_bw() to prepare for moving the BW allocation from encoder hooks up to intel_atomic_commit_tail() later in the patchset. - Disable BW alloc mode during system suspend. - Allocate the required BW for all tunnels during system resume. - Add intel_dp_tunnel_atomic_clear_stream_bw() instead of the open-coded sequence in a follow-up patch. - Add function documentation to all exported functions. - Add CONFIG_USB4 dependency to CONFIG_DRM_I915_DP_TUNNEL. v3: - Rebase on intel_dp_get_active_pipes() change in previous patch. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Uma Shankar <uma.shankar@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240226185246.1276018-4-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.