diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0297-vchiq_arm-Add-completion-records-under-the-mutex.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0297-vchiq_arm-Add-completion-records-under-the-mutex.patch | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0297-vchiq_arm-Add-completion-records-under-the-mutex.patch b/target/linux/brcm2708/patches-4.4/0297-vchiq_arm-Add-completion-records-under-the-mutex.patch new file mode 100644 index 0000000000..8075b63a88 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0297-vchiq_arm-Add-completion-records-under-the-mutex.patch @@ -0,0 +1,63 @@ +From 3ea5efb1f91da877b375eccb94e1cd4517fd8638 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Thu, 21 Apr 2016 13:49:32 +0100 +Subject: [PATCH 297/423] vchiq_arm: Add completion records under the mutex + +An issue was observed when flushing openmax components +which generate a large number of messages returning +buffers to host. + +We occasionally found a duplicate message from 16 +messages prior, resulting in a buffer returned twice. + +While only one thread adds completions, without the +mutex you don't get the protection of the automatic +memory barrier you get with synchronisation objects. + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + drivers/misc/vc04_services/interface/vchiq_arm/vchiq_arm.c | 13 ++++++++++++- + 1 file changed, 12 insertions(+), 1 deletion(-) + +--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_arm.c ++++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_arm.c +@@ -210,6 +210,8 @@ add_completion(VCHIQ_INSTANCE_T instance + VCHIQ_COMPLETION_DATA_T *completion; + DEBUG_INITIALISE(g_state.local) + ++ mutex_lock(&instance->completion_mutex); ++ + while (instance->completion_insert == + (instance->completion_remove + MAX_COMPLETIONS)) { + /* Out of space - wait for the client */ +@@ -217,11 +219,17 @@ add_completion(VCHIQ_INSTANCE_T instance + vchiq_log_trace(vchiq_arm_log_level, + "add_completion - completion queue full"); + DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT); ++ ++ mutex_unlock(&instance->completion_mutex); + if (down_interruptible(&instance->remove_event) != 0) { + vchiq_log_info(vchiq_arm_log_level, + "service_callback interrupted"); + return VCHIQ_RETRY; +- } else if (instance->closing) { ++ } ++ ++ mutex_lock(&instance->completion_mutex); ++ if (instance->closing) { ++ mutex_unlock(&instance->completion_mutex); + vchiq_log_info(vchiq_arm_log_level, + "service_callback closing"); + return VCHIQ_SUCCESS; +@@ -254,8 +262,11 @@ add_completion(VCHIQ_INSTANCE_T instance + if (reason == VCHIQ_MESSAGE_AVAILABLE) + user_service->message_available_pos = + instance->completion_insert; ++ + instance->completion_insert++; + ++ mutex_unlock(&instance->completion_mutex); ++ + up(&instance->insert_event); + + return VCHIQ_SUCCESS; |