Re: [PATCH 2/3] Revert "staging: vchiq_arm: Create keep-alive thread during probe"

Am 13.07.25 um 20:40 schrieb Maíra Canal:

Hi Stefan,

On 11/07/25 12:40, Stefan Wahren wrote:

quoted

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)?

Sure

I mistakenly sent the e-mail reporting using my university e-mail.

quoted

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

---
  .../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[] = {