Re: [RFC][PATCH v3 12/33] timers: dma-buf: Use timer_shutdown_sync() before freeing timer

Christian König
2022-11-04T07:16:07Z

Am 04.11.22 um 06:54 schrieb Steven Rostedt:
> [ Once again, quilt fails the MIME coding ]
>
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> Before a timer is freed, timer_shutdown_sync() must be called.
>
> Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20220407161745.7d6754b3%40gandalf.local.home%2F&amp;data=05%7C01%7Cchristian.koenig%40amd.com%7Ca18ff1d0a7e442a1283808dabe29148d%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C638031380931371691%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=XZgwOy0u20L1AxOjhUpWICodbSn2VYhh6YGSykjUegQ%3D&amp;reserved=0
>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: linux-media@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: linaro-mm-sig@lists.linaro.org
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> drivers/dma-buf/st-dma-fence.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c
> index fb6e0a6ae2c9..5d3e7b503501 100644
> --- a/drivers/dma-buf/st-dma-fence.c
> +++ b/drivers/dma-buf/st-dma-fence.c
> @@ -412,7 +412,7 @@ static int test_wait_timeout(void *arg)
>
> err = 0;
> err_free:
> - del_timer_sync(&wt.timer);
> + timer_shutdown_sync(&wt.timer);

Mhm, what exactly is the benefit of renaming the function?

Not that I'm against the change, but my thinking is more if there are
more functions which don't re-arm the time than those which do that then
why not forbid it in general?

Regards,
Christian.

> destroy_timer_on_stack(&wt.timer);
> dma_fence_signal(wt.f);
> dma_fence_put(wt.f);