[PATCH v16 03/16] accel/rocket: wait for a running IRQ handler before resetting a core

[Jiaxing Hu]

drm_sched_stop() does not wait for a threaded IRQ handler that is already
running, so call synchronize_irq() after it to make sure the handler has
finished before the reset.

Before synchronize_irq(), mask the interrupt and clear the raw status, so
that the NPU core cannot report a completion afterwards.

Do this under job_lock, because the submit path sets the interrupt mask
under the same lock.

Only touch these registers when the device is powered: check with
pm_runtime_get_if_active(), so that a register access with the power
domain off cannot raise an SError.

Suggested-by: Igor Paunovic <royalnet026 at gmail.com>
Signed-off-by: Jiaxing Hu <gahing at gahingwoo.com>
Tested-by: Igor Paunovic <royalnet026 at gmail.com> # RK3588, three cores, induced reset, JOB_TIMEOUT_MS=2
---
 drivers/accel/rocket/rocket_job.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/accel/rocket/rocket_job.c b/drivers/accel/rocket/rocket_job.c
index 03e5f094f60b..abef12b86d48 100644
--- a/drivers/accel/rocket/rocket_job.c
+++ b/drivers/accel/rocket/rocket_job.c
@@ -400,6 +400,16 @@ rocket_reset(struct rocket_core *core, struct drm_sched_job *bad)
 
 	drm_sched_stop(&core->sched, bad);
 
+	scoped_guard(mutex, &core->job_lock) {
+		if (pm_runtime_get_if_active(core->dev) > 0) {
+			rocket_pc_writel(core, INTERRUPT_MASK, 0x0);
+			rocket_pc_writel(core, INTERRUPT_CLEAR, 0x1ffff);
+			pm_runtime_put_autosuspend(core->dev);
+		}
+	}
+
+	synchronize_irq(core->irq);
+
 	/*
 	 * Remaining interrupts have been handled, but we might still have
 	 * stuck jobs. Let's make sure the PM counters stay balanced by
-- 
2.43.0