V4L/DVB (11616): cx18: Add a work queue for deferring empty buffer handoffs to the...

[net-next-2.6.git] / drivers / media / video / cx18 / cx18-driver.c

diff --git a/drivers/media/video/cx18/cx18-driver.c b/drivers/media/video/cx18/cx18-driver.c
index 79750208e042ac54337c9fcfcbdd98beb92dcf84..658cfbb1b97e066890fd7ec5d47d37d434a98205 100644 (file)
--- a/drivers/media/video/cx18/cx18-driver.c
+++ b/drivers/media/video/cx18/cx18-driver.c
@@ -546,6 +546,47 @@ done:
        cx->card_i2c = cx->card->i2c;
 }
 
+static int __devinit cx18_create_in_workq(struct cx18 *cx)
+{
+       snprintf(cx->in_workq_name, sizeof(cx->in_workq_name), "%s-in",
+                cx->v4l2_dev.name);
+       cx->in_work_queue = create_singlethread_workqueue(cx->in_workq_name);
+       if (cx->in_work_queue == NULL) {
+               CX18_ERR("Unable to create incoming mailbox handler thread\n");
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+static int __devinit cx18_create_out_workq(struct cx18 *cx)
+{
+       snprintf(cx->out_workq_name, sizeof(cx->out_workq_name), "%s-out",
+                cx->v4l2_dev.name);
+       cx->out_work_queue = create_workqueue(cx->out_workq_name);
+       if (cx->out_work_queue == NULL) {
+               CX18_ERR("Unable to create outgoing mailbox handler threads\n");
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+static void __devinit cx18_init_in_work_orders(struct cx18 *cx)
+{
+       int i;
+       for (i = 0; i < CX18_MAX_IN_WORK_ORDERS; i++) {
+               cx->in_work_order[i].cx = cx;
+               cx->in_work_order[i].str = cx->epu_debug_str;
+               INIT_WORK(&cx->in_work_order[i].work, cx18_in_work_handler);
+       }
+}
+
+static void __devinit cx18_init_out_work_orders(struct cx18 *cx)
+{
+       int i;
+       for (i = 0; i < CX18_MAX_OUT_WORK_ORDERS; i++)
+               INIT_WORK(&cx->out_work_order[i].work, cx18_out_work_handler);
+}
+
 /* Precondition: the cx18 structure has been memset to 0. Only
    the dev and instance fields have been filled in.
    No assumptions on the card type may be made here (see cx18_init_struct2
@@ -553,7 +594,7 @@ done:
  */
 static int __devinit cx18_init_struct1(struct cx18 *cx)
 {
-       int i;
+       int ret;
 
        cx->base_addr = pci_resource_start(cx->pci_dev, 0);
 
@@ -562,20 +603,19 @@ static int __devinit cx18_init_struct1(struct cx18 *cx)
        mutex_init(&cx->epu2apu_mb_lock);
        mutex_init(&cx->epu2cpu_mb_lock);
 
-       snprintf(cx->in_workq_name, sizeof(cx->in_workq_name), "%s-in",
-                cx->v4l2_dev.name);
-       cx->in_work_queue = create_singlethread_workqueue(cx->in_workq_name);
-       if (cx->in_work_queue == NULL) {
-               CX18_ERR("Unable to create incoming mailbox handler thread\n");
-               return -ENOMEM;
-       }
+       ret = cx18_create_out_workq(cx);
+       if (ret)
+               return ret;
 
-       for (i = 0; i < CX18_MAX_IN_WORK_ORDERS; i++) {
-               cx->in_work_order[i].cx = cx;
-               cx->in_work_order[i].str = cx->epu_debug_str;
-               INIT_WORK(&cx->in_work_order[i].work, cx18_in_work_handler);
+       ret = cx18_create_in_workq(cx);
+       if (ret) {
+               destroy_workqueue(cx->out_work_queue);
+               return ret;
        }
 
+       cx18_init_out_work_orders(cx);
+       cx18_init_in_work_orders(cx);
+
        /* start counting open_id at 1 */
        cx->open_id = 1;
 
@@ -761,17 +801,17 @@ static int __devinit cx18_probe(struct pci_dev *pci_dev,
                retval = -ENODEV;
                goto err;
        }
-       if (cx18_init_struct1(cx)) {
-               retval = -ENOMEM;
+
+       retval = cx18_init_struct1(cx);
+       if (retval)
                goto err;
-       }
 
        CX18_DEBUG_INFO("base addr: 0x%08x\n", cx->base_addr);
 
        /* PCI Device Setup */
        retval = cx18_setup_pci(cx, pci_dev, pci_id);
        if (retval != 0)
-               goto free_workqueue;
+               goto free_workqueues;
 
        /* map io memory */
        CX18_DEBUG_INFO("attempting ioremap at 0x%08x len 0x%08x\n",
@@ -945,8 +985,9 @@ free_map:
        cx18_iounmap(cx);
 free_mem:
        release_mem_region(cx->base_addr, CX18_MEM_SIZE);
-free_workqueue:
+free_workqueues:
        destroy_workqueue(cx->in_work_queue);
+       destroy_workqueue(cx->out_work_queue);
 err:
        if (retval == 0)
                retval = -ENODEV;
@@ -1075,15 +1116,26 @@ static void cx18_remove(struct pci_dev *pci_dev)
        if (atomic_read(&cx->tot_capturing) > 0)
                cx18_stop_all_captures(cx);
 
-       /* Interrupts */
+       /* Stop interrupts that cause incoming work to be queued */
        cx18_sw1_irq_disable(cx, IRQ_CPU_TO_EPU | IRQ_APU_TO_EPU);
+
+       /* Incoming work can cause outgoing work, so clean up incoming first */
+       cx18_cancel_in_work_orders(cx);
+
+       /*
+        * An outgoing work order can have the only pointer to a dynamically
+        * allocated buffer, so we need to flush outgoing work and not just
+        * cancel it, so we don't lose the pointer and leak memory.
+        */
+       flush_workqueue(cx->out_work_queue);
+
+       /* Stop ack interrupts that may have been needed for work to finish */
        cx18_sw2_irq_disable(cx, IRQ_CPU_TO_EPU_ACK | IRQ_APU_TO_EPU_ACK);
 
        cx18_halt_firmware(cx);
 
-       cx18_cancel_in_work_orders(cx);
-
        destroy_workqueue(cx->in_work_queue);
+       destroy_workqueue(cx->out_work_queue);
 
        cx18_streams_cleanup(cx, 1);