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Lyude Paul d3e2c664ec drm/amdgpu/dm/mst: Use the correct topology mgr pointer in amdgpu_dm_connector 
This bug hurt me. Basically, it appears that we've been grabbing the
entirely wrong mutex in the MST DSC computation code for amdgpu! While
we've been grabbing:

  amdgpu_dm_connector->mst_mgr

That's zero-initialized memory, because the only connectors we'll ever
actually be doing DSC computations for are MST ports. Which have mst_mgr
zero-initialized, and instead have the correct topology mgr pointer located
at:

  amdgpu_dm_connector->mst_port->mgr;

I'm a bit impressed that until now, this code has managed not to crash
anyone's systems! It does seem to cause a warning in LOCKDEP though:

  [   66.637670] DEBUG_LOCKS_WARN_ON(lock->magic != lock)

This was causing the problems that appeared to have been introduced by:

  commit 4d07b0bc40 ("drm/display/dp_mst: Move all payload info into the atomic state")

This wasn't actually where they came from though. Presumably, before the
only thing we were doing with the topology mgr pointer was attempting to
grab mst_mgr->lock. Since the above commit however, we grab much more
information from mst_mgr including the atomic MST state and respective
modesetting locks.

This patch also implies that up until now, it's quite likely we could be
susceptible to race conditions when going through the MST topology state
for DSC computations since we technically will not have grabbed any lock
when going through it.

So, let's fix this by adjusting all the respective code paths to look at
the right pointer and skip things that aren't actual MST connectors from a
topology.

Gitlab issue: https://gitlab.freedesktop.org/drm/amd/-/issues/2171

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 8c20a1ed9b ("drm/amd/display: MST DSC compute fair share")
Cc: <stable@vger.kernel.org> # v5.6+
Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2022-11-17 00:22:34 -05:00
arch Xilinx ZynqMP DisplayPort bridge support 2022-10-27 14:44:15 +10:00
block block-6.1-2022-10-20 2022-10-21 15:14:14 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation Merge tag 'drm-intel-gt-next-2022-11-03' of git://anongit.freedesktop.org/drm/drm-intel into drm-next 2022-11-04 17:33:34 +10:00
drivers drm/amdgpu/dm/mst: Use the correct topology mgr pointer in amdgpu_dm_connector 2022-11-17 00:22:34 -05:00
fs First batch of EFI fixes for v6.1 2022-10-21 18:02:36 -07:00
include drm/amdgpu: revert "implement tdr advanced mode" 2022-11-15 15:25:22 -05:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring/net: fail zc sendmsg when unsupported by socket 2022-10-22 08:43:03 -06:00
ipc - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
kernel kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
lib Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/huge_memory: do not clobber swp_entry_t during THP split 2022-10-20 21:27:24 -07:00
net io_uring-6.1-2022-10-22 2022-10-23 09:55:50 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts Kbuild fixes for v6.1 2022-10-16 11:12:22 -07:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
sound sound fixes for 6.1-rc1 2022-10-14 13:22:14 -07:00
tools RISC-V: 2022-10-23 15:00:43 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-22 05:15:23 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -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 drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
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 Merge tag 'drm-intel-gt-next-2022-11-03' of git://anongit.freedesktop.org/drm/drm-intel into drm-next 2022-11-04 17:33:34 +10:00
Makefile Linux 6.1-rc2 2022-10-23 15:27:33 -07:00
README

README 

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.