2021-10-21 08:45:49

by Cai,Huoqing

Subject: [PATCH] staging: vchiq_arm: Make use of the helper macro kthread_run()

Repalce kthread_create/wake_up_process() with kthread_run()
to simplify the code.

Signed-off-by: Cai Huoqing <[email protected]>
---
.../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index a5e33da74726..6130b95aaca3 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -1717,15 +1717,12 @@ void vchiq_platform_conn_state_changed(struct vchiq_state *state,
write_unlock_bh(&arm_state->susp_res_lock);
snprintf(threadname, sizeof(threadname), "vchiq-keep/%d",
state->id);
- arm_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func,
- (void *)state,
- threadname);
+ arm_state->ka_thread = kthread_run(&vchiq_keepalive_thread_func,
+ (void *)state, threadname);
if (IS_ERR(arm_state->ka_thread)) {
vchiq_log_error(vchiq_susp_log_level,
"vchiq: FATAL: couldn't create thread %s",
threadname);
- } else {
- wake_up_process(arm_state->ka_thread);
}
}

--
2.25.1

2021-10-22 09:05:39

by Greg Kroah-Hartman

Subject: Re: [PATCH] staging: vchiq_arm: Make use of the helper macro kthread_run()

On Thu, Oct 21, 2021 at 04:43:27PM +0800, Cai Huoqing wrote:
> Repalce kthread_create/wake_up_process() with kthread_run()
> to simplify the code.
>
> Signed-off-by: Cai Huoqing <[email protected]>
> ---
> .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> index a5e33da74726..6130b95aaca3 100644
> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> @@ -1717,15 +1717,12 @@ void vchiq_platform_conn_state_changed(struct vchiq_state *state,
> write_unlock_bh(&arm_state->susp_res_lock);
> snprintf(threadname, sizeof(threadname), "vchiq-keep/%d",
> state->id);
> - arm_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func,
> - (void *)state,
> - threadname);
> + arm_state->ka_thread = kthread_run(&vchiq_keepalive_thread_func,
> + (void *)state, threadname);
> if (IS_ERR(arm_state->ka_thread)) {
> vchiq_log_error(vchiq_susp_log_level,
> "vchiq: FATAL: couldn't create thread %s",
> threadname);
> - } else {
> - wake_up_process(arm_state->ka_thread);
> }
> }
>

As others have pointed out for other busses where you sent this patch,
this is _VERY_ racy and probably wrong. Be more careful when sending
changes like this that can modify functionality without testing the
code.

thanks,

greg k-h