Hello!

On 11.01.2021 7:40, Davidlohr Bueso wrote:

Tasklets have long been deprecated as being too heavy on the system
by running in irq context - and this is not a performance critical
path. If a higher priority process wants to run, it must wait for
the tasklet to finish before doing so.

c67x00_do_work() will now run in process context and have further
concurrency (tasklets being serialized among themselves), but this
is done holding the c67x00->lock, so it should be fine. Furthermore,
this patch fixes the usage of the lock in the callback as otherwise
it would need to be irq-safe.

Signed-off-by: Davidlohr Bueso <dbu...@suse.de>
[...]
diff --git a/drivers/usb/c67x00/c67x00-sched.c 
b/drivers/usb/c67x00/c67x00-sched.c
index e65f1a0ae80b..af60f4fdd340 100644
--- a/drivers/usb/c67x00/c67x00-sched.c
+++ b/drivers/usb/c67x00/c67x00-sched.c
@@ -1123,24 +1123,26 @@ static void c67x00_do_work(struct c67x00_hcd *c67x00)
/* -------------------------------------------------------------------------- */ -static void c67x00_sched_tasklet(struct tasklet_struct *t)
+static void c67x00_sched_work(struct work_struct *work)
  {
-       struct c67x00_hcd *c67x00 = from_tasklet(c67x00, t, tasklet);
+       struct c67x00_hcd *c67x00;
+
+       c67x00 = container_of(work, struct c67x00_hcd, work);
        c67x00_do_work(c67x00);
  }
void c67x00_sched_kick(struct c67x00_hcd *c67x00)
  {
-       tasklet_hi_schedule(&c67x00->tasklet);
+        queue_work(system_highpri_wq, &c67x00->work);

    Use a tab to indent, please.

  }
int c67x00_sched_start_scheduler(struct c67x00_hcd *c67x00)
  {
-       tasklet_setup(&c67x00->tasklet, c67x00_sched_tasklet);
+        INIT_WORK(&c67x00->work, c67x00_sched_work);

   Here as well.

        return 0;
  }
void c67x00_sched_stop_scheduler(struct c67x00_hcd *c67x00)
  {
-       tasklet_kill(&c67x00->tasklet);
+        cancel_work_sync(&c67x00->work);

   And here.

[...]

MBR, Sergei

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