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Gustavo Sousa bdcdb913c2 drm/i915/dmc_wl: Do not check for DMC payload
Enabling and disabling of DMC wakelock is already coupled with enabling
and disabling of dynamic DC states, which already depend on the DMC
being properly loaded. As such, we do not need to check if we already
have a DMC payload parsed in __intel_dmc_wl_supported().

Furthermore, the presence of such a check causes inconsistencies in the
refcount if the following sequence of events happen:

  1. A call to one of the register accessors from intel_de.h is done
     before the DMC payload is parsed. That causes intel_dmc_wl_get() to
     be called. Suppose the register offset qualifies as needing the
     wakelock.

     In normal circumstances, the refcount would be incremented, but,
     because __intel_dmc_wl_supported() returns false, the refcount is
     untouched.

  2. In a separate worker thread, the DMC firmware is parsed. Parsing of
     the DMC payload is finished before the corresponding
     intel_dmc_wl_put() from (1) is called.

  3. When in the context of (1), intel_dmc_wl_put() gets called, now we
     have __intel_dmc_wl_supported() returning true and we hit the
     warning, because the code doesn't expect a zero refcount.

Let's remove that check, since it is unnecessary and causes the
inconsistency illustrated above.

Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250124191250.56833-1-gustavo.sousa@intel.com
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
2025-02-05 10:50:58 -03:00
arch drm-misc-next for 6.14: 2024-12-20 08:24:34 +10:00
block block: Fix potential deadlock while freezing queue and acquiring sysfs_lock 2024-12-13 10:51:58 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: rsassa-pkcs1 - Copy source data for SG list 2024-12-10 13:34:05 +08:00
Documentation drm-misc-next for 6.14: 2024-12-20 08:24:34 +10:00
drivers drm/i915/dmc_wl: Do not check for DMC payload 2025-02-05 10:50:58 -03:00
fs First batch of EFI fixes for v6.13 2024-12-15 15:33:41 -08:00
include drm/i915/lspcon: do not hardcode settle timeout 2025-01-27 14:54:46 -05:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring/rsrc: don't put/free empty buffers 2024-12-12 08:01:52 -07:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel - Prevent incorrect dequeueing of the deadline dlserver helper task and fix 2024-12-15 09:38:03 -08:00
lib drm-misc-next for 6.14: 2024-12-20 08:24:34 +10:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm slab fixes for 6.13-rc3 2024-12-13 09:43:50 -08:00
net BPF fixes: 2024-12-14 12:58:14 -08:00
rust rust: kbuild: set bindgen's Rust target version 2024-12-10 01:06:10 +01:00
samples BPF fixes: 2024-12-06 15:07:48 -08:00
scripts A single fix for a docs-build regression caused by the EXPORT_SYMBOL_NS() 2024-12-13 09:46:02 -08:00
security Including fixes from can and netfilter. 2024-12-05 10:25:06 -08:00
sound ASoC: Fixes for v6.13 2024-12-12 14:49:35 +01:00
tools BPF fixes: 2024-12-14 12:58:14 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: enable Clippy's check-private-items 2024-10-07 21:39:57 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap media updates for v6.13-rc1 2024-11-20 14:01:15 -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 cgroup: Changes for v6.13 2024-11-20 09:54:49 -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: switch my mail address for GVT driver 2025-01-09 16:08:43 -05:00
Makefile Linux 6.13-rc3 2024-12-15 15:58:23 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.