+++ /dev/null
-From 522f1499310d389e663a4e8dd0ccbb916b768766 Mon Sep 17 00:00:00 2001
-From: Dave Stevenson <dave.stevenson@raspberrypi.org>
-Date: Wed, 14 Feb 2018 17:04:26 +0000
-Subject: [PATCH] staging: bcm2835-camera: Do not bulk receive from
- service thread
-
-vchi_bulk_queue_receive will queue up to a default of 4
-bulk receives on a connection before blocking.
-If called from the VCHI service_callback thread, then
-that thread is unable to service the VCHI_CALLBACK_BULK_RECEIVED
-events that would enable the queue call to succeed.
-
-Add a workqueue to schedule the call vchi_bulk_queue_receive
-in an alternate context to avoid the lock up.
-
-Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
----
- .../vc04_services/bcm2835-camera/mmal-vchiq.c | 101 ++++++++++--------
- 1 file changed, 59 insertions(+), 42 deletions(-)
-
---- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
-+++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
-@@ -118,8 +118,10 @@ struct mmal_msg_context {
-
- union {
- struct {
-- /* work struct for defered callback - must come first */
-+ /* work struct for buffer_cb callback */
- struct work_struct work;
-+ /* work struct for deferred callback */
-+ struct work_struct buffer_to_host_work;
- /* mmal instance */
- struct vchiq_mmal_instance *instance;
- /* mmal port */
-@@ -168,6 +170,9 @@ struct vchiq_mmal_instance {
- /* component to use next */
- int component_idx;
- struct vchiq_mmal_component component[VCHIQ_MMAL_MAX_COMPONENTS];
-+
-+ /* ordered workqueue to process all bulk operations */
-+ struct workqueue_struct *bulk_wq;
- };
-
- static struct mmal_msg_context *
-@@ -251,7 +256,44 @@ static void buffer_work_cb(struct work_s
- msg_context->u.bulk.mmal_flags,
- msg_context->u.bulk.dts,
- msg_context->u.bulk.pts);
-+}
-
-+/* workqueue scheduled callback to handle receiving buffers
-+ *
-+ * VCHI will allow up to 4 bulk receives to be scheduled before blocking.
-+ * If we block in the service_callback context then we can't process the
-+ * VCHI_CALLBACK_BULK_RECEIVED message that would otherwise allow the blocked
-+ * vchi_bulk_queue_receive() call to complete.
-+ */
-+static void buffer_to_host_work_cb(struct work_struct *work)
-+{
-+ struct mmal_msg_context *msg_context =
-+ container_of(work, struct mmal_msg_context,
-+ u.bulk.buffer_to_host_work);
-+ struct vchiq_mmal_instance *instance = msg_context->instance;
-+ unsigned long len = msg_context->u.bulk.buffer_used;
-+ int ret;
-+
-+ if (!len)
-+ /* Dummy receive to ensure the buffers remain in order */
-+ len = 8;
-+ /* queue the bulk submission */
-+ vchi_service_use(instance->handle);
-+ ret = vchi_bulk_queue_receive(instance->handle,
-+ msg_context->u.bulk.buffer->buffer,
-+ /* Actual receive needs to be a multiple
-+ * of 4 bytes
-+ */
-+ (len + 3) & ~3,
-+ VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE |
-+ VCHI_FLAGS_BLOCK_UNTIL_QUEUED,
-+ msg_context);
-+
-+ vchi_service_release(instance->handle);
-+
-+ if (ret != 0)
-+ pr_err("%s: ctx: %p, vchi_bulk_queue_receive failed %d\n",
-+ __func__, msg_context, ret);
- }
-
- /* enqueue a bulk receive for a given message context */
-@@ -260,7 +302,6 @@ static int bulk_receive(struct vchiq_mma
- struct mmal_msg_context *msg_context)
- {
- unsigned long rd_len;
-- int ret;
-
- rd_len = msg->u.buffer_from_host.buffer_header.length;
-
-@@ -294,45 +335,10 @@ static int bulk_receive(struct vchiq_mma
- msg_context->u.bulk.dts = msg->u.buffer_from_host.buffer_header.dts;
- msg_context->u.bulk.pts = msg->u.buffer_from_host.buffer_header.pts;
-
-- /* queue the bulk submission */
-- vchi_service_use(instance->handle);
-- ret = vchi_bulk_queue_receive(instance->handle,
-- msg_context->u.bulk.buffer->buffer,
-- /* Actual receive needs to be a multiple
-- * of 4 bytes
-- */
-- (rd_len + 3) & ~3,
-- VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE |
-- VCHI_FLAGS_BLOCK_UNTIL_QUEUED,
-- msg_context);
--
-- vchi_service_release(instance->handle);
-+ queue_work(msg_context->instance->bulk_wq,
-+ &msg_context->u.bulk.buffer_to_host_work);
-
-- return ret;
--}
--
--/* enque a dummy bulk receive for a given message context */
--static int dummy_bulk_receive(struct vchiq_mmal_instance *instance,
-- struct mmal_msg_context *msg_context)
--{
-- int ret;
--
-- /* zero length indicates this was a dummy transfer */
-- msg_context->u.bulk.buffer_used = 0;
--
-- /* queue the bulk submission */
-- vchi_service_use(instance->handle);
--
-- ret = vchi_bulk_queue_receive(instance->handle,
-- instance->bulk_scratch,
-- 8,
-- VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE |
-- VCHI_FLAGS_BLOCK_UNTIL_QUEUED,
-- msg_context);
--
-- vchi_service_release(instance->handle);
--
-- return ret;
-+ return 0;
- }
-
- /* data in message, memcpy from packet into output buffer */
-@@ -380,6 +386,8 @@ buffer_from_host(struct vchiq_mmal_insta
-
- /* initialise work structure ready to schedule callback */
- INIT_WORK(&msg_context->u.bulk.work, buffer_work_cb);
-+ INIT_WORK(&msg_context->u.bulk.buffer_to_host_work,
-+ buffer_to_host_work_cb);
-
- atomic_inc(&port->buffers_with_vpu);
-
-@@ -465,7 +473,7 @@ static void buffer_to_host_cb(struct vch
- if (msg->u.buffer_from_host.buffer_header.flags &
- MMAL_BUFFER_HEADER_FLAG_EOS) {
- msg_context->u.bulk.status =
-- dummy_bulk_receive(instance, msg_context);
-+ bulk_receive(instance, msg, msg_context);
- if (msg_context->u.bulk.status == 0)
- return; /* successful bulk submission, bulk
- * completion will trigger callback
-@@ -1789,6 +1797,9 @@ int vchiq_mmal_finalise(struct vchiq_mma
-
- mutex_unlock(&instance->vchiq_mutex);
-
-+ flush_workqueue(instance->bulk_wq);
-+ destroy_workqueue(instance->bulk_wq);
-+
- vfree(instance->bulk_scratch);
-
- idr_destroy(&instance->context_map);
-@@ -1858,6 +1869,11 @@ int vchiq_mmal_init(struct vchiq_mmal_in
-
- params.callback_param = instance;
-
-+ instance->bulk_wq = alloc_ordered_workqueue("mmal-vchiq",
-+ WQ_MEM_RECLAIM);
-+ if (!instance->bulk_wq)
-+ goto err_free;
-+
- status = vchi_service_open(vchi_instance, ¶ms, &instance->handle);
- if (status) {
- pr_err("Failed to open VCHI service connection (status=%d)\n",
-@@ -1872,8 +1888,9 @@ int vchiq_mmal_init(struct vchiq_mmal_in
- return 0;
-
- err_close_services:
--
- vchi_service_close(instance->handle);
-+ destroy_workqueue(instance->bulk_wq);
-+err_free:
- vfree(instance->bulk_scratch);
- kfree(instance);
- return -ENODEV;
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