Re: [PATCH v2 0/4] drm/tyr: implement GPU reset API

[Boqun Feng <boqun@kernel.org>]

On Thu, Apr 16, 2026 at 08:23:45PM +0300, Onur Özkan wrote:
> On Thu, 16 Apr 2026 20:17:26 +0300
> Onur Özkan <work@onurozkan.dev> wrote:
> 
> > This series adds GPU reset handling support for Tyr in a new module
> > drivers/gpu/drm/tyr/driver.rs which encapsulates the low-level reset
> > controller internals and exposes a ResetHandle API to the driver.
> > 
> > This series is based on Alice's "Creation of workqueues in Rust" [1]
> > series.
> > 
> > Changes since v1:
> >   - Removed OrderedQueue and using Alice's workqueue implementation [1] instead.
> >   - Added Resettable trait with pre_reset and post_reset hooks to be implemented by
> >     reset-managed hardwares.
> >   - Added SRCU abstraction and used it to synchronize the reset work and hardware access.
> > 
> > 3 important points:
> >   - There is no hardware using this API yet.
> >   - On post_reset() failure, we don't do anything for now. We should unplug the GPU (that's
> >     what Panthor does) but we don't have the infrastructure for that yet (see [2]).
> >   - In schedule(), similar to panthor_device_schedule_reset(), we should have a PM check
> >     but similar to the note above, we don't have the infrastructure for that yet.
> > 
> > Link: https://lore.kernel.org/all/20260312-create-workqueue-v4-0-ea39c351c38f@google.com/ [1]
> > Link: https://gitlab.freedesktop.org/panfrost/linux/-/work_items/29#note_3391826 [2]
> > Link: https://gitlab.freedesktop.org/panfrost/linux/-/issues/28
> > 
> > Onur Özkan (4):
> >   rust: add SRCU abstraction
> >   MAINTAINERS: add Rust SRCU files to SRCU entry
> >   rust: add Work::disable_sync
> >   drm/tyr: add reset management API
> > 
> >  MAINTAINERS                          |   3 +
> >  drivers/gpu/drm/tyr/driver.rs        |  40 +---
> >  drivers/gpu/drm/tyr/reset.rs         | 293 +++++++++++++++++++++++++++
> >  drivers/gpu/drm/tyr/reset/hw_gate.rs | 155 ++++++++++++++
> >  drivers/gpu/drm/tyr/tyr.rs           |   1 +
> >  rust/helpers/helpers.c               |   1 +
> >  rust/helpers/srcu.c                  |  18 ++
> >  rust/kernel/sync.rs                  |   2 +
> >  rust/kernel/sync/srcu.rs             | 109 ++++++++++
> >  rust/kernel/workqueue/mod.rs         |  15 ++
> >  10 files changed, 607 insertions(+), 30 deletions(-)
> >  create mode 100644 drivers/gpu/drm/tyr/reset.rs
> >  create mode 100644 drivers/gpu/drm/tyr/reset/hw_gate.rs
> >  create mode 100644 rust/helpers/srcu.c
> >  create mode 100644 rust/kernel/sync/srcu.rs
> > 
> > -- 
> > 2.51.2
> > 
> 
> I messed up when sending the series (part of it was sent as a separate series
> [1]. I will resend this properly, sorry for the noise.
> 

FWIW, I didn't receive your patch #3 (even from my subscription on
rust-for-linux list).

Could you add a doc test for disable_sync(), I'm curious about it
because you may disable a work that has not be executed yet, and
wouldn't that be leaking memory (IIUC, we rely on Arc::drop() in
WorkItemPointer::run() to decrease the refcounts), but maybe I'm missing
something subtle.

Regards,
Boqun

> [1]: https://lore.kernel.org/all/20260416171728.205141-1-work@onurozkan.dev/
> 
> -Onur
>