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Ville Syrjälä 6a8c66bf0e drm/i915: Don't explode when the dig port we don't have an AUX CH
The icl+ power well code currently assumes that every AUX power
well maps to an encoder which is using said power well. That is
by no menas guaranteed as we:
- only register encoders for ports declared in the VBT
- combo PHY HDMI-only encoder no longer get an AUX CH since
  commit 9856308c94 ("drm/i915: Only populate aux_ch if really needed")

However we have places such as intel_power_domains_sanitize_state()
that blindly traverse all the possible power wells. So these bits
of code may very well encounbter an aux power well with no associated
encoder.

In this particular case the BIOS seems to have left one AUX power
well enabled even though we're dealing with a HDMI only encoder
on a combo PHY. We then proceed to turn off said power well and
explode when we can't find a matching encoder. As a short term fix
we should be able to just skip the PHY related parts of the power
well programming since we know this situation can only happen with
combo PHYs.

Another option might be to go back to always picking an AUX CH for
all encoders. However I'm a bit wary about that since we might in
theory end up conflicting with the VBT AUX CH assignment. Also
that wouldn't help with encoders not declared in the VBT, should
we ever need to poke the corresponding power wells.

Longer term we need to figure out what the actual relationship
is between the PHY vs. AUX CH vs. AUX power well. Currently this
is entirely unclear.

Cc: stable@vger.kernel.org
Fixes: 9856308c94 ("drm/i915: Only populate aux_ch if really needed")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10184
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240223203216.15210-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
2024-02-29 20:49:37 +02:00
arch Linux 6.8-rc6 2024-02-26 11:41:07 +01:00
block block: sed-opal: handle empty atoms when parsing response 2024-02-16 15:52:45 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: algif_hash - Remove bogus SGL free on zero-length error path 2024-02-02 18:08:12 +08:00
Documentation Linux 6.8-rc6 2024-02-26 11:41:07 +01:00
drivers drm/i915: Don't explode when the dig port we don't have an AUX CH 2024-02-29 20:49:37 +02:00
fs bcachefs fixes for 6.8-rc6 2024-02-25 15:31:57 -08:00
include Merge tag 'drm-intel-next-2024-02-27-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-next 2024-02-28 11:02:55 +10:00
init update workarounds for gcc "asm goto" issue 2024-02-15 11:14:33 -08:00
io_uring io_uring/net: fix multishot accept overflow handling 2024-02-14 18:30:19 -07:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel Including fixes from bpf and netfilter. 2024-02-22 09:57:58 -08:00
lib lib/Kconfig.debug: TEST_IOV_ITER depends on MMU 2024-02-20 14:20:48 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
net l2tp: pass correct message length to ip6_append_data 2024-02-22 10:42:17 +01:00
rust Rust changes for v6.8 2024-01-11 13:05:41 -08:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
scripts Including fixes from bpf and netfilter. 2024-02-22 09:57:58 -08:00
security lsm/stable-6.8 PR 20240215 2024-02-16 07:58:43 -08:00
sound ALSA: usb-audio: More relaxed check of MIDI jack names 2024-02-15 16:56:05 +01:00
tools cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt Generic: 2024-01-17 13:03:37 -08:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.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 Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap MAINTAINERS: mailmap: update Shakeel's email address 2024-02-20 14:20:50 -08:00
.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 MAINTAINERS: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
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 MAINTAINERS: Update drm.git URL 2024-02-27 13:47:01 +01:00
Makefile Linux 6.8-rc6 2024-02-25 15:46:06 -08:00
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.