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Lyude Paul bbb9293c9b drm/nouveau/gsp: Increase delay for magic sleep in r535_gsp_fini()
As it turns out, Turing isn't the only architecture that needs this. On
this Dell Precision 7780 with an AD103 GPU, along with pretty much every
other laptop I tested, runtime PM is still somewhat unreliable. At first
glance it seems as if it's fixed, but lowering the autosuspend delay to
500ms and then doing a stress test of suspend/resume cycles on the GPU ends
up causing everything to start timing out.

After quite a lot of digging, I eventually landed back on this magic
timeout in r535_gsp_fini(). As it turns out, increasing the timeout ends up
fixing the runtime PM issues as far as I can tell, even during intense
stress testing.

Unfortunately after spending quite a bit of time trying to dig through
OpenRM to figure out what this magic sleep is actually doing, I've also
come up short with any reasonable explanation. In lieu of that, I'm going
to include the observations I did make while trying to figure this out in
hopes someone eventually does figure this out:

* The magic sleep has to occur after fbsr is initialized. Performing it at
  any time before that doesn't appear to work.
* In situations where runtime PM starts getting flaky, some rather
  interesting visual effects end up happening on occasion before the GPU
  fully falls over. In particular, squares that look like the result of an
  incomplete blitting operation to a tiled buffer end up showing up on
  applications like vkcube. Interestingly enough, they remain in precisely
  the same place between runtime PM cycles until the GPU falls over - even
  when restarting vkcube multiple times, and even when vkcube is actively
  updating the screen. Even more interestingly, they're not limited to a
  specific framebuffer - you can see the squares changing as the cube
  rotates around.
  We cannot however, say that this is likely to be a incomplete fbsr
  operation. The magic sleep happens before fbsr is actually saved (which
  happens on the GSP unload), so it's something else.
* During a short bit of testing with a desktop that I have, the magic sleep
  seemed to make no difference to whether or not suspend/resume works. It
  seems to generally work almost always. So we can assume this is likely
  exclusive to runtime PM, not S3.

As well, here's a list of the things I tried before settling on the magic
sleep:

* Hooking up NV2080_CTRL_CMD_INTERNAL_GCX_ENTRY_PREREQUISITE and then
  blocking runtime PM until OpenRM signals that GC6/GCOFF is ready appears
  to make no difference.
* Hooking up some (maybe not all, unsure about that part) bits of comptag
  saving including:
  * Fetching static memsys information from GSP
  * Adding the size of the comptag storage to the fbsr data
  * Adding a GA103+ workaround for disabling raw compression mode during
    fbsr (it doesn't seem like it applies for any systems I tried it on
    anyhow)
  * Setting bPreserveVideoMemoryAllocations=1 in GspSystemInfo

So, until we can figure this out properly - just sleep for longer.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 53dac06238 ("drm/nouveau/gsp: add support for 570.144")
Cc: <stable@vger.kernel.org> # v6.16+
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260814194542.781955-5-lyude@redhat.com
(cherry picked from commit 09b47186a4)
Signed-off-by: Lyude Paul <lyude@redhat.com>
History 2026-09-11 13:26:18 -04:00
arch bpf-fixes 2026-09-06 13:49:44 -07:00
block block: save page offset gaps in cloned bio 2026-09-01 08:42:34 -06:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto This push fixes a memory allocation overrun in crypto acomp. 2026-08-28 09:28:40 -07:00
Documentation Miscellaneous IRQ subsystem fixes: 2026-09-06 10:35:24 -07:00
drivers drm/nouveau/gsp: Increase delay for magic sleep in r535_gsp_fini() 2026-09-11 13:26:18 -04:00
fs kmalloc_obj conversions for v7.3-rc2 2026-09-05 20:45:18 -07:00
include tracing fixes for v7.3: 2026-09-06 14:21:24 -07:00
init treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
io_uring treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
ipc mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
kernel tracing fixes for v7.3: 2026-09-06 14:21:24 -07:00
lib treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
net kmalloc_obj conversions for v7.3-rc2 2026-09-05 20:45:18 -07:00
rust rust: pci: reject IRQ vector indices that do not fit in u32 2026-09-01 18:21:01 +02:00
samples tracing fixes for v7.3: 2026-08-30 09:22:00 -07:00
scripts Coccinelle patches for Linux v7.3 2026-08-30 10:42:40 -07:00
security kmalloc_obj conversions for v7.3-rc2 2026-09-05 20:45:18 -07:00
sound treewide: refresh kmalloc_obj() conversions 2026-09-04 21:37:00 -07:00
tools bpf-fixes 2026-09-06 13:49:44 -07:00
usr usr: Correct a spelling by changing a letter 2026-08-05 14:51:58 +02:00
virt Arm: 2026-08-25 11:48:04 -07:00
.clang-format drm/bridge: rename drm_for_each_bridge_in_chain_scoped() to drm_for_each_bridge_in_chain() 2026-07-14 17:55:51 +02:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add Nathan Chancellor 2026-08-03 21:10:12 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore SPDX patches for 7.2-rc1 2026-06-22 12:06:22 -07:00
.mailmap drm fixes for 7.3-rc2 2026-09-04 13:42:16 -07:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -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 Driver core fixes for 7.3-rc2 2026-09-05 11:59:05 -07:00
Kbuild checksyscalls: move instance functionality into generic code 2026-04-05 09:21:32 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Driver core fixes for 7.3-rc2 2026-09-05 11:59:05 -07:00
Makefile Linux 7.3-rc2 2026-09-06 15:07:20 -07:00
README README: remove out of place emdashes 2026-07-15 10:51:29 -06:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer: Getting started with kernel development
* Academic Researcher: Studying kernel internals and architecture
* Security Expert: Hardening and vulnerability analysis
* Backport/Maintenance Engineer: Maintaining stable kernels
* System Administrator: Configuring and troubleshooting
* Maintainer: Leading subsystems and reviewing patches
* Hardware Vendor: Writing drivers for new hardware
* Distribution Maintainer: Packaging kernels for distros
* AI Coding Assistant: LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst