[PATCH v2 0/3] Rework panthor's cache flush and soft reset locking

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

There are two problems in panthor's cache flushing/soft reset code
related to locking.

The first problem is that the spinlocks are taken with _irqsave, even
though the contended lock is never acquired in a raw interrupt handler.
Only a threaded handler locks it.

The second problem is that the wait_event condition references
pending_reqs without holding the required lock. This means there's a
data race.

While resolving the first problem is easy, the second problem requires
adding some more macro variants to wait.h, which is done in the first
patch.

New tracepoints to debug cache flushing duration without initial locking
waits is thrown in for good measure as well, to complement what's in
lock_stat and what the function tracer can already do.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
Changes in v2:
- Use trace event template for the two tracepoints (ty Steven Rostedt)
- Link to v1: https://patch.msgid.link/20260729-panthor-cache-flush-fix-v1-0-205921ed3c81@collabora.com

---
Nicolas Frattaroli (3):
      wait: Introduce non-irq variants of wait_event_lock_timeout
      drm/panthor: Revisit reqs_lock handling in flush/reset paths
      drm/panthor: Add tracepoints for cache flushing

 drivers/gpu/drm/panthor/panthor_gpu.c   | 28 +++++------
 drivers/gpu/drm/panthor/panthor_trace.h | 49 +++++++++++++++++++
 include/linux/wait.h                    | 84 +++++++++++++++++++++++++++++++++
 3 files changed, 147 insertions(+), 14 deletions(-)
---
base-commit: 5e24f68d311764bf343f9def49b752b509dfd5fd
change-id: 20260728-panthor-cache-flush-fix-b36cb15f92c3

Best regards,
--  
Nicolas Frattaroli <nicolas.frattaroli@collabora.com>