Re: [PATCH 2/3] Revert "staging: vchiq_arm: Create keep-alive thread during probe"
From: Maíra Canal <mcanal@igalia.com>
Date: 2025-07-13 18:43:24
Also in:
linux-staging
Hi Stefan, On 11/07/25 12:40, Stefan Wahren wrote:
The commit 86bc88217006 ("staging: vchiq_arm: Create keep-alive thread
during probe") introduced a regression for certain configurations,
which doesn't have a VCHIQ user. This results in a unused and hanging
keep-alive thread:
INFO: task vchiq-keep/0:85 blocked for more than 120 seconds.
Not tainted 6.12.34-v8-+ #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:vchiq-keep/0 state:D stack:0 pid:85 tgid:85 ppid:2
Call trace:
__switch_to+0x188/0x230
__schedule+0xa54/0xb28
schedule+0x80/0x120
schedule_preempt_disabled+0x30/0x50
kthread+0xd4/0x1a0
ret_from_fork+0x10/0x20
Fixes: 86bc88217006 ("staging: vchiq_arm: Create keep-alive thread during probe")
Reported-by: Maíra Canal <redacted>If possible, could you use my Igalia e-mail instead (mcanal@igalia.com)? I mistakenly sent the e-mail reporting using my university e-mail.
Closes: https://lore.kernel.org/linux-staging/ba35b960-a981-4671-9f7f-060da10feaa1@usp.br/ (local) Cc: <stable@kernel.org> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Maíra Canal <mcanal@igalia.com> Best Regards, - Maíra
quoted hunk ↗ jump to hunk
--- .../interface/vchiq_arm/vchiq_arm.c | 69 ++++++++++--------- 1 file changed, 35 insertions(+), 34 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 cdf5687ad4f0..6434cbdc1a6e 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c@@ -280,6 +280,29 @@ static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state return 0; } +int +vchiq_platform_init_state(struct vchiq_state *state) +{ + struct vchiq_arm_state *platform_state; + + platform_state = devm_kzalloc(state->dev, sizeof(*platform_state), GFP_KERNEL); + if (!platform_state) + return -ENOMEM; + + rwlock_init(&platform_state->susp_res_lock); + + init_completion(&platform_state->ka_evt); + atomic_set(&platform_state->ka_use_count, 0); + atomic_set(&platform_state->ka_use_ack_count, 0); + atomic_set(&platform_state->ka_release_count, 0); + + platform_state->state = state; + + state->platform_state = (struct opaque_platform_state *)platform_state; + + return 0; +} + static struct vchiq_arm_state *vchiq_platform_get_arm_state(struct vchiq_state *state) { return (struct vchiq_arm_state *)state->platform_state;@@ -988,39 +1011,6 @@ vchiq_keepalive_thread_func(void *v) return 0; } -int -vchiq_platform_init_state(struct vchiq_state *state) -{ - struct vchiq_arm_state *platform_state; - char threadname[16]; - - platform_state = devm_kzalloc(state->dev, sizeof(*platform_state), GFP_KERNEL); - if (!platform_state) - return -ENOMEM; - - snprintf(threadname, sizeof(threadname), "vchiq-keep/%d", - state->id); - platform_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func, - (void *)state, threadname); - if (IS_ERR(platform_state->ka_thread)) { - dev_err(state->dev, "couldn't create thread %s\n", threadname); - return PTR_ERR(platform_state->ka_thread); - } - - rwlock_init(&platform_state->susp_res_lock); - - init_completion(&platform_state->ka_evt); - atomic_set(&platform_state->ka_use_count, 0); - atomic_set(&platform_state->ka_use_ack_count, 0); - atomic_set(&platform_state->ka_release_count, 0); - - platform_state->state = state; - - state->platform_state = (struct opaque_platform_state *)platform_state; - - return 0; -} - int vchiq_use_internal(struct vchiq_state *state, struct vchiq_service *service, enum USE_TYPE_E use_type)@@ -1341,6 +1331,7 @@ void vchiq_platform_conn_state_changed(struct vchiq_state *state, enum vchiq_connstate newstate) { struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state); + char threadname[16]; dev_dbg(state->dev, "suspend: %d: %s->%s\n", state->id, get_conn_state_name(oldstate), get_conn_state_name(newstate));@@ -1355,7 +1346,17 @@ void vchiq_platform_conn_state_changed(struct vchiq_state *state, arm_state->first_connect = 1; write_unlock_bh(&arm_state->susp_res_lock); - wake_up_process(arm_state->ka_thread); + snprintf(threadname, sizeof(threadname), "vchiq-keep/%d", + state->id); + arm_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func, + (void *)state, + threadname); + if (IS_ERR(arm_state->ka_thread)) { + dev_err(state->dev, "suspend: Couldn't create thread %s\n", + threadname); + } else { + wake_up_process(arm_state->ka_thread); + } } static const struct of_device_id vchiq_of_match[] = {