Go to file
Lyude Paul d4373630fd drm/nouveau/disp/nv50-: Set lock_core in curs507a_prepare
commit 9e9bc6be0fa0b6b6b73f4f831f3b77716d0a8d9e upstream.

For a while, I've been seeing a strange issue where some (usually not all)
of the display DMA channels will suddenly hang, particularly when there is
a visible cursor on the screen that is being frequently updated, and
especially when said cursor happens to go between two screens. While this
brings back lovely memories of fixing Intel Skylake bugs, I would quite
like to fix it :).

It turns out the problem that's happening here is that we're managing to
reach nv50_head_flush_set() in our atomic commit path without actually
holding nv50_disp->mutex. This means that cursor updates happening in
parallel (along with any other atomic updates that need to use the core
channel) will race with eachother, which eventually causes us to corrupt
the pushbuffer - leading to a plethora of various GSP errors, usually:

  nouveau 0000:c1:00.0: gsp: Xid:56 CMDre 00000000 00000218 00102680 00000004 00800003
  nouveau 0000:c1:00.0: gsp: Xid:56 CMDre 00000000 0000021c 00040509 00000004 00000001
  nouveau 0000:c1:00.0: gsp: Xid:56 CMDre 00000000 00000000 00000000 00000001 00000001

The reason this is happening is because generally we check whether we need
to set nv50_atom->lock_core at the end of nv50_head_atomic_check().
However, curs507a_prepare is called from the fb_prepare callback, which
happens after the atomic check phase. As a result, this can lead to commits
that both touch the core channel but also don't grab nv50_disp->mutex.

So, fix this by making sure that we set nv50_atom->lock_core in
cus507a_prepare().

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 1590700d94 ("drm/nouveau/kms/nv50-: split each resource type into their own source files")
Cc: <stable@vger.kernel.org> # v4.18+
Link: https://patch.msgid.link/20251219215344.170852-2-lyude@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23 11:21:31 +01:00
arch LoongArch: dts: Describe PCI sideband IRQ through interrupt-extended 2026-01-23 11:21:30 +01:00
block block: zero non-PI portion of auto integrity buffer 2026-01-23 11:21:16 +01:00
certs
crypto crypto: seqiv - Do not use req->iv after crypto_aead_encrypt 2026-01-08 10:16:43 +01:00
Documentation dt-bindings: PCI: qcom,pcie-sm8550: Add missing required power-domains and resets 2026-01-02 12:57:27 +01:00
drivers drm/nouveau/disp/nv50-: Set lock_core in curs507a_prepare 2026-01-23 11:21:31 +01:00
fs ext4: fix iloc.bh leak in ext4_xattr_inode_update_ref 2026-01-23 11:21:28 +01:00
include ext4: fix ext4_tune_sb_params padding 2026-01-23 11:21:28 +01:00
init printk changes for 6.18 2025-10-04 11:13:11 -07:00
io_uring io_uring: move local task_work in exit cancel loop 2026-01-23 11:21:13 +01:00
ipc namespace-6.18-rc1 2025-09-29 11:20:29 -07:00
kernel hrtimer: Fix softirq base check in update_needs_ipi() 2026-01-23 11:21:28 +01:00
lib lib/buildid: use __kernel_read() for sleepable context 2026-01-23 11:21:25 +01:00
LICENSES
mm mm/damon/sysfs: cleanup attrs subdirs on context dir setup failure 2026-01-23 11:21:30 +01:00
net net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts 2026-01-23 11:21:24 +01:00
rust rust: bitops: fix missing _find_* functions on 32-bit ARM 2026-01-23 11:21:12 +01:00
samples samples/ftrace: Adjust LoongArch register restore order in direct calls 2026-01-08 10:17:11 +01:00
scripts mcb: Add missing modpost build support 2026-01-08 10:16:47 +01:00
security landlock: Fix wrong type usage 2026-01-23 11:21:22 +01:00
sound ASoC: codecs: wsa881x: fix unnecessary initialisation 2026-01-23 11:21:28 +01:00
tools tools/testing/selftests: fix gup_longterm for unknown fs 2026-01-23 11:21:25 +01:00
usr gen_init_cpio: Ignore fsync() returning EINVAL on pipes 2025-10-07 09:53:05 -07:00
virt KVM: Fix last_boosted_vcpu index assignment bug 2026-01-02 12:57:21 +01:00
.clang-format
.clippy.toml
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap 8 hotfixes. 4 are cc:stable, 7 are against mm/. 2025-11-26 12:38:05 -08:00
.pylintrc
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: mark ISDN subsystem as orphan 2025-10-27 17:49:45 -07:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig
MAINTAINERS soc: fixes for 6.18, part 4 2025-11-28 09:57:31 -08:00
Makefile Linux 6.18.6 2026-01-17 16:35:34 +01:00
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 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.