Imre Deak 998d2cd361 drm/i915/fdi: Improve FDI BW sharing between pipe B and C
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
2023-09-28 12:52:26 +03:00
…
…
2023-09-10 16:28:41 -07:00
…

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.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%