[PATCH v14 02/15] accel/rocket: take the completion register writes under job_lock

[Jiaxing Hu]

rocket_job_handle_irq() writes OPERATION_ENABLE and INTERRUPT_CLEAR before
taking job_lock, while rocket_job_hw_submit() writes OPERATION_ENABLE under
it, so a completion can write its zero after a submit has written its one
and stop a task that has just started. Move both writes inside the existing
scoped_guard().

Fixes: 0810d5ad88a1 ("accel/rocket: Add job submission IOCTL")
Signed-off-by: Jiaxing Hu <gah...@gahingwoo.com>
Tested-by: Igor Paunovic <royalnet...@gmail.com> # RK3588, three cores, induced 
reset, JOB_TIMEOUT_MS=2
---
 drivers/accel/rocket/rocket_job.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/accel/rocket/rocket_job.c 
b/drivers/accel/rocket/rocket_job.c
index f40435505..575945015 100644
--- a/drivers/accel/rocket/rocket_job.c
+++ b/drivers/accel/rocket/rocket_job.c
@@ -345,10 +345,15 @@ static void rocket_job_handle_irq(struct rocket_core 
*core)
 {
        pm_runtime_mark_last_busy(core->dev);
 
-       rocket_pc_writel(core, OPERATION_ENABLE, 0x0);
-       rocket_pc_writel(core, INTERRUPT_CLEAR, 0x1ffff);
+       scoped_guard(mutex, &core->job_lock) {
+               /*
+                * Stopping the block belongs under the lock. hw_submit() writes
+                * OPERATION_ENABLE too, and outside the lock this zero can land
+                * after that one and stop a task that has only just started.
+                */
+               rocket_pc_writel(core, OPERATION_ENABLE, 0x0);
+               rocket_pc_writel(core, INTERRUPT_CLEAR, 0x1ffff);
 
-       scoped_guard(mutex, &core->job_lock)
                if (core->in_flight_job) {
                        if (core->in_flight_job->next_task_idx < 
core->in_flight_job->task_count) {
                                rocket_job_hw_submit(core, core->in_flight_job);
@@ -360,6 +365,7 @@ static void rocket_job_handle_irq(struct rocket_core *core)
                        pm_runtime_put_autosuspend(core->dev);
                        core->in_flight_job = NULL;
                }
+       }
 }
 
 static void
-- 
2.43.0