From ebe0b2ecb7b8285852414a0f20044432e37d9b4c Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Tue, 15 Jul 2025 18:11:06 +0200 Subject: [PATCH 1/3] Revert "staging: vchiq_arm: Improve initial VCHIQ connect" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The commit 3e5def4249b9 ("staging: vchiq_arm: Improve initial VCHIQ connect") based on the assumption that in good case the VCHIQ connect always happen and therefore the keep-alive thread is guaranteed to be woken up. This is wrong, because in certain configurations there are no VCHIQ users and so the VCHIQ connect never happen. So revert it. Fixes: 3e5def4249b9 ("staging: vchiq_arm: Improve initial VCHIQ connect") Reported-by: Maíra Canal Closes: https://lore.kernel.org/linux-staging/ba35b960-a981-4671-9f7f-060da10feaa1@usp.br/ Cc: stable@kernel.org Signed-off-by: Stefan Wahren Reviewed-by: Maíra Canal Link: https://lore.kernel.org/r/20250715161108.3411-2-wahrenst@gmx.net Signed-off-by: Greg Kroah-Hartman --- .../interface/vchiq_arm/vchiq_arm.c | 28 ++++++++++++++----- .../interface/vchiq_arm/vchiq_core.c | 1 - .../interface/vchiq_arm/vchiq_core.h | 2 -- 3 files changed, 21 insertions(+), 10 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 5dbf8d53db09..cdf5687ad4f0 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -97,6 +97,13 @@ struct vchiq_arm_state { * tracked separately with the state. */ int peer_use_count; + + /* + * Flag to indicate that the first vchiq connect has made it through. + * This means that both sides should be fully ready, and we should + * be able to suspend after this point. + */ + int first_connect; }; static int @@ -1329,19 +1336,26 @@ vchiq_check_service(struct vchiq_service *service) return ret; } -void vchiq_platform_connected(struct vchiq_state *state) -{ - struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state); - - wake_up_process(arm_state->ka_thread); -} - void vchiq_platform_conn_state_changed(struct vchiq_state *state, enum vchiq_connstate oldstate, enum vchiq_connstate newstate) { + struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state); + dev_dbg(state->dev, "suspend: %d: %s->%s\n", state->id, get_conn_state_name(oldstate), get_conn_state_name(newstate)); + if (state->conn_state != VCHIQ_CONNSTATE_CONNECTED) + return; + + write_lock_bh(&arm_state->susp_res_lock); + if (arm_state->first_connect) { + write_unlock_bh(&arm_state->susp_res_lock); + return; + } + + arm_state->first_connect = 1; + write_unlock_bh(&arm_state->susp_res_lock); + wake_up_process(arm_state->ka_thread); } static const struct of_device_id vchiq_of_match[] = { diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c index e7b0c800a205..e2cac0898b8f 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c @@ -3343,7 +3343,6 @@ vchiq_connect_internal(struct vchiq_state *state, struct vchiq_instance *instanc return -EAGAIN; vchiq_set_conn_state(state, VCHIQ_CONNSTATE_CONNECTED); - vchiq_platform_connected(state); complete(&state->connect); } diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h index 3b5c0618e567..9b4e766990a4 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h @@ -575,8 +575,6 @@ int vchiq_send_remote_use(struct vchiq_state *state); int vchiq_send_remote_use_active(struct vchiq_state *state); -void vchiq_platform_connected(struct vchiq_state *state); - void vchiq_platform_conn_state_changed(struct vchiq_state *state, enum vchiq_connstate oldstate, enum vchiq_connstate newstate); From 228af5a58524fba09ec4b7d184694db4f7fe96f5 Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Tue, 15 Jul 2025 18:11:07 +0200 Subject: [PATCH 2/3] Revert "staging: vchiq_arm: Create keep-alive thread during probe" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Closes: https://lore.kernel.org/linux-staging/ba35b960-a981-4671-9f7f-060da10feaa1@usp.br/ Cc: stable@kernel.org Signed-off-by: Stefan Wahren Reviewed-by: Maíra Canal Link: https://lore.kernel.org/r/20250715161108.3411-3-wahrenst@gmx.net Signed-off-by: Greg Kroah-Hartman --- .../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[] = { From f2b8ebfb867011ddbefbdf7b04ad62626cbc2afd Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Tue, 15 Jul 2025 18:11:08 +0200 Subject: [PATCH 3/3] staging: vchiq_arm: Make vchiq_shutdown never fail Most of the users of vchiq_shutdown ignore the return value, which is bad because this could lead to resource leaks. So instead of changing all calls to vchiq_shutdown, it's easier to make vchiq_shutdown never fail. Fixes: 71bad7f08641 ("staging: add bcm2708 vchiq driver") Signed-off-by: Stefan Wahren Link: https://lore.kernel.org/r/20250715161108.3411-4-wahrenst@gmx.net Signed-off-by: Greg Kroah-Hartman --- drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 3 +-- 1 file changed, 1 insertion(+), 2 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 6434cbdc1a6e..721b15b7e13b 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -393,8 +393,7 @@ int vchiq_shutdown(struct vchiq_instance *instance) struct vchiq_state *state = instance->state; int ret = 0; - if (mutex_lock_killable(&state->mutex)) - return -EAGAIN; + mutex_lock(&state->mutex); /* Remove all services */ vchiq_shutdown_internal(state, instance);