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Imre Deak 8ca0b875c0 drm/i915: Add helpers for BW management on shared display links
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
2023-09-28 12:52:22 +03:00
arch Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, 2023-09-10 10:39:31 -07:00
block block: fix pin count management when merging same-page segments 2023-09-06 07:32:27 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto This update includes the following changes: 2023-08-29 11:23:29 -07:00
Documentation drm ci for 6.6-rc1 2023-09-10 11:55:26 -07:00
drivers drm/i915: Add helpers for BW management on shared display links 2023-09-28 12:52:22 +03:00
fs six smb3 client fixes, one fix for nls Kconfig, one minor spnego registry update 2023-09-09 19:56:23 -07:00
include Merge drm/drm-next into drm-intel-next 2023-09-15 11:23:38 +03:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring Revert "io_uring: fix IO hang in io_wq_put_and_exit from do_exit()" 2023-09-07 09:41:49 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
lib iov_iter: Kunit tests for page extraction 2023-09-09 15:11:49 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
net Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, 2023-09-10 10:39:31 -07:00
security Landlock updates for v6.6-rc1 2023-09-08 12:06:51 -07:00
sound sound fixes for 6.6-rc1 2023-09-08 13:07:50 -07:00
tools perf tools changes for v6.6: 2023-09-09 20:06:17 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm ci for 6.6-rc1 2023-09-10 11:55:26 -07:00
Makefile Linux 6.6-rc1 2023-09-10 16:28:41 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.