ivtv: use kthread_worker instead of workqueue

Upcoming workqueue updates will no longer guarantee fixed workqueue to
worker kthread association, so giving RT priority to the irq worker
won't work.  Use kthread_worker which guarantees specific kthread
association instead.  This also makes setting the priority cleaner.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: ivtv-devel@ivtvdriver.org
Cc: linux-media@vger.kernel.org

4 files changed, 24 insertions, 27 deletions

diff --git a/drivers/media/video/ivtv/ivtv-driver.c b/drivers/media/video/ivtv/ivtv-driver.c
index 1b79475ca134..49e0b1cc3544 100644
--- a/drivers/media/video/ivtv/ivtv-driver.c
+++ b/drivers/media/video/ivtv/ivtv-driver.c
@@ -695,6 +695,8 @@ done:
  */
 static int __devinit ivtv_init_struct1(struct ivtv *itv)
 {
+        struct sched_param param = { .sched_priority = 99 };
+
         itv->base_addr = pci_resource_start(itv->pdev, 0);
         itv->enc_mbox.max_mbox = 2; /* the encoder has 3 mailboxes (0-2) */
         itv->dec_mbox.max_mbox = 1; /* the decoder has 2 mailboxes (0-1) */
@@ -706,13 +708,17 @@ static int __devinit ivtv_init_struct1(struct ivtv *itv)
         spin_lock_init(&itv->lock);
         spin_lock_init(&itv->dma_reg_lock);
 
-        itv->irq_work_queues = create_singlethread_workqueue(itv->v4l2_dev.name);
-        if (itv->irq_work_queues == NULL) {
-                IVTV_ERR("Could not create ivtv workqueue\n");
+        init_kthread_worker(&itv->irq_worker);
+        itv->irq_worker_task = kthread_run(kthread_worker_fn, &itv->irq_worker,
+                                           itv->v4l2_dev.name);
+        if (IS_ERR(itv->irq_worker_task)) {
+                IVTV_ERR("Could not create ivtv task\n");
                 return -1;
         }
+        /* must use the FIFO scheduler as it is realtime sensitive */
+        sched_setscheduler(itv->irq_worker_task, SCHED_FIFO, &param);
 
-        INIT_WORK(&itv->irq_work_queue, ivtv_irq_work_handler);
+        init_kthread_work(&itv->irq_work, ivtv_irq_work_handler);
 
         /* start counting open_id at 1 */
         itv->open_id = 1;
@@ -996,7 +1002,7 @@ static int __devinit ivtv_probe(struct pci_dev *pdev,
         /* PCI Device Setup */
         retval = ivtv_setup_pci(itv, pdev, pci_id);
         if (retval == -EIO)
-                goto free_workqueue;
+                goto free_worker;
         if (retval == -ENXIO)
                 goto free_mem;
 
@@ -1208,8 +1214,8 @@ free_mem:
         release_mem_region(itv->base_addr + IVTV_REG_OFFSET, IVTV_REG_SIZE);
         if (itv->has_cx23415)
                 release_mem_region(itv->base_addr + IVTV_DECODER_OFFSET, IVTV_DECODER_SIZE);
-free_workqueue:
-        destroy_workqueue(itv->irq_work_queues);
+free_worker:
+        kthread_stop(itv->irq_worker_task);
 err:
         if (retval == 0)
                 retval = -ENODEV;
@@ -1353,9 +1359,9 @@ static void ivtv_remove(struct pci_dev *pdev)
         ivtv_set_irq_mask(itv, 0xffffffff);
         del_timer_sync(&itv->dma_timer);
 
-        /* Stop all Work Queues */
-        flush_workqueue(itv->irq_work_queues);
-        destroy_workqueue(itv->irq_work_queues);
+        /* Kill irq worker */
+        flush_kthread_worker(&itv->irq_worker);
+        kthread_stop(itv->irq_worker_task);
 
         ivtv_streams_cleanup(itv, 1);
         ivtv_udma_free(itv);
diff --git a/drivers/media/video/ivtv/ivtv-driver.h b/drivers/media/video/ivtv/ivtv-driver.h
index 5b45fd2b2645..51f7f2a9cf5e 100644
--- a/drivers/media/video/ivtv/ivtv-driver.h
+++ b/drivers/media/video/ivtv/ivtv-driver.h
@@ -51,7 +51,7 @@
 #include <linux/unistd.h>
 #include <linux/pagemap.h>
 #include <linux/scatterlist.h>
-#include <linux/workqueue.h>
+#include <linux/kthread.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <asm/uaccess.h>
@@ -257,7 +257,6 @@ struct ivtv_mailbox_data {
 #define IVTV_F_I_DEC_PAUSED        20   /* the decoder is paused */
 #define IVTV_F_I_INITED            21   /* set after first open */
 #define IVTV_F_I_FAILED            22   /* set if first open failed */
-#define IVTV_F_I_WORK_INITED       23   /* worker thread was initialized */
 
 /* Event notifications */
 #define IVTV_F_I_EV_DEC_STOPPED    28   /* decoder stopped event */
@@ -663,8 +662,9 @@ struct ivtv {
         /* Interrupts & DMA */
         u32 irqmask;                    /* active interrupts */
         u32 irq_rr_idx;                 /* round-robin stream index */
-        struct workqueue_struct *irq_work_queues;       /* workqueue for PIO/YUV/VBI actions */
-        struct work_struct irq_work_queue;              /* work entry */
+        struct kthread_worker irq_worker;               /* kthread worker for PIO/YUV/VBI actions */
+        struct task_struct *irq_worker_task;            /* task for irq_worker */
+        struct kthread_work irq_work;   /* kthread work entry */
         spinlock_t dma_reg_lock;        /* lock access to DMA engine registers */
         int cur_dma_stream;             /* index of current stream doing DMA (-1 if none) */
         int cur_pio_stream;             /* index of current stream doing PIO (-1 if none) */
diff --git a/drivers/media/video/ivtv/ivtv-irq.c b/drivers/media/video/ivtv/ivtv-irq.c
index fea1ec33b0df..9b4faf009196 100644
--- a/drivers/media/video/ivtv/ivtv-irq.c
+++ b/drivers/media/video/ivtv/ivtv-irq.c
@@ -71,19 +71,10 @@ static void ivtv_pio_work_handler(struct ivtv *itv)
         write_reg(IVTV_IRQ_ENC_PIO_COMPLETE, 0x44);
 }
 
-void ivtv_irq_work_handler(struct work_struct *work)
+void ivtv_irq_work_handler(struct kthread_work *work)
 {
-        struct ivtv *itv = container_of(work, struct ivtv, irq_work_queue);
+        struct ivtv *itv = container_of(work, struct ivtv, irq_work);
 
-        DEFINE_WAIT(wait);
-
-        if (test_and_clear_bit(IVTV_F_I_WORK_INITED, &itv->i_flags)) {
-                struct sched_param param = { .sched_priority = 99 };
-
-                /* This thread must use the FIFO scheduler as it
-                   is realtime sensitive. */
-                sched_setscheduler(current, SCHED_FIFO, &param);
-        }
         if (test_and_clear_bit(IVTV_F_I_WORK_HANDLER_PIO, &itv->i_flags))
                 ivtv_pio_work_handler(itv);
 
@@ -975,7 +966,7 @@ irqreturn_t ivtv_irq_handler(int irq, void *dev_id)
         }
 
         if (test_and_clear_bit(IVTV_F_I_HAVE_WORK, &itv->i_flags)) {
-                queue_work(itv->irq_work_queues, &itv->irq_work_queue);
+                queue_kthread_work(&itv->irq_worker, &itv->irq_work);
         }
 
         spin_unlock(&itv->dma_reg_lock);
diff --git a/drivers/media/video/ivtv/ivtv-irq.h b/drivers/media/video/ivtv/ivtv-irq.h
index f879a5822e71..1e84433737cc 100644
--- a/drivers/media/video/ivtv/ivtv-irq.h
+++ b/drivers/media/video/ivtv/ivtv-irq.h
@@ -46,7 +46,7 @@
 
 irqreturn_t ivtv_irq_handler(int irq, void *dev_id);
 
-void ivtv_irq_work_handler(struct work_struct *work);
+void ivtv_irq_work_handler(struct kthread_work *work);
 void ivtv_dma_stream_dec_prepare(struct ivtv_stream *s, u32 offset, int lock);
 void ivtv_unfinished_dma(unsigned long arg);