Re: [PATCH 2/2] media: venus: sync with threaded IRQ during inst destruction

From: Sergey Senozhatsky
Date: Thu Oct 24 2024 - 01:13:53 EST


On (24/10/24 13:58), Sergey Senozhatsky wrote:
> Date: Thu, 24 Oct 2024 13:58:36 +0900
> From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
> To: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
> Cc: Stanimir Varbanov <stanimir.k.varbanov@xxxxxxxxx>, Vikash Garodia
> <quic_vgarodia@xxxxxxxxxxx>, Bryan O'Donoghue
> <bryan.odonoghue@xxxxxxxxxx>, linux-media@xxxxxxxxxxxxxxx,
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 2/2] media: venus: sync with threaded IRQ during inst
> destruction
> Message-ID: <20241024045836.GJ1279924@xxxxxxxxxx>
>
> On (24/10/23 14:24), Sergey Senozhatsky wrote:
> > Guard inst destruction (both dec and enc) with hard and threaded
> > IRQ synchronization.
>
> Folks, please ignore this patch. Stand by for v2.

I think it probably should be something like this (both for dec and
enc).

---

@@ -1538,9 +1538,25 @@ static int venc_close(struct file *file)

venc_pm_get(inst);

+ /*
+ * First, remove the inst from the ->instances list, so that
+ * to_instance() will return NULL.
+ */
+ hfi_session_destroy(inst);
+ /*
+ * Second, make sure we don't have IRQ/IRQ-thread currently running or
+ * pending execution (disable_irq() calls synchronize_irq()), which
+ * can race with the inst destruction.
+ */
+ disable_irq(inst->core->irq);
+ /*
+ * Lastly, inst is gone from the core->instances list and we don't
+ * have running/pending IRQ/IRQ-thread, proceed with the destruction
+ */
+ enable_irq(inst->core->irq);
+
v4l2_m2m_ctx_release(inst->m2m_ctx);
v4l2_m2m_release(inst->m2m_dev);
- hfi_session_destroy(inst);
v4l2_fh_del(&inst->fh);
v4l2_fh_exit(&inst->fh);
venc_ctrl_deinit(inst);