1 files changed, 50 insertions, 23 deletions

diff --git a/drivers/media/dvb/pt1/pt1.c b/drivers/media/dvb/pt1/pt1.c
index b81df5fafe26..463f7849c44c 100644
--- a/drivers/media/dvb/pt1/pt1.c
+++ b/drivers/media/dvb/pt1/pt1.c
@@ -77,6 +77,8 @@ struct pt1 {
 	struct pt1_adapter *adaps[PT1_NR_ADAPS];
 	struct pt1_table *tables;
 	struct task_struct *kthread;
+	int table_index;
+	int buf_index;
 
 	struct mutex lock;
 	int power;
@@ -303,30 +305,25 @@ static int pt1_filter(struct pt1 *pt1, struct pt1_buffer_page *page)
 static int pt1_thread(void *data)
 {
 	struct pt1 *pt1;
-	int table_index;
-	int buf_index;
 	struct pt1_buffer_page *page;
 
 	pt1 = data;
 	set_freezable();
 
-	table_index = 0;
-	buf_index = 0;
-
 	while (!kthread_should_stop()) {
 		try_to_freeze();
 
-		page = pt1->tables[table_index].bufs[buf_index].page;
+		page = pt1->tables[pt1->table_index].bufs[pt1->buf_index].page;
 		if (!pt1_filter(pt1, page)) {
 			schedule_timeout_interruptible((HZ + 999) / 1000);
 			continue;
 		}
 
-		if (++buf_index >= PT1_NR_BUFS) {
+		if (++pt1->buf_index >= PT1_NR_BUFS) {
 			pt1_increment_table_count(pt1);
-			buf_index = 0;
-			if (++table_index >= pt1_nr_tables)
-				table_index = 0;
+			pt1->buf_index = 0;
+			if (++pt1->table_index >= pt1_nr_tables)
+				pt1->table_index = 0;
 		}
 	}
 
@@ -477,21 +474,60 @@ err:
 	return ret;
 }
 
+static int pt1_start_polling(struct pt1 *pt1)
+{
+	int ret = 0;
+
+	mutex_lock(&pt1->lock);
+	if (!pt1->kthread) {
+		pt1->kthread = kthread_run(pt1_thread, pt1, "earth-pt1");
+		if (IS_ERR(pt1->kthread)) {
+			ret = PTR_ERR(pt1->kthread);
+			pt1->kthread = NULL;
+		}
+	}
+	mutex_unlock(&pt1->lock);
+	return ret;
+}
+
 static int pt1_start_feed(struct dvb_demux_feed *feed)
 {
 	struct pt1_adapter *adap;
 	adap = container_of(feed->demux, struct pt1_adapter, demux);
-	if (!adap->users++)
+	if (!adap->users++) {
+		int ret;
+
+		ret = pt1_start_polling(adap->pt1);
+		if (ret)
+			return ret;
 		pt1_set_stream(adap->pt1, adap->index, 1);
+	}
 	return 0;
 }
 
+static void pt1_stop_polling(struct pt1 *pt1)
+{
+	int i, count;
+
+	mutex_lock(&pt1->lock);
+	for (i = 0, count = 0; i < PT1_NR_ADAPS; i++)
+		count += pt1->adaps[i]->users;
+
+	if (count == 0 && pt1->kthread) {
+		kthread_stop(pt1->kthread);
+		pt1->kthread = NULL;
+	}
+	mutex_unlock(&pt1->lock);
+}
+
 static int pt1_stop_feed(struct dvb_demux_feed *feed)
 {
 	struct pt1_adapter *adap;
 	adap = container_of(feed->demux, struct pt1_adapter, demux);
-	if (!--adap->users)
+	if (!--adap->users) {
 		pt1_set_stream(adap->pt1, adap->index, 0);
+		pt1_stop_polling(adap->pt1);
+	}
 	return 0;
 }
 
@@ -1020,7 +1056,8 @@ static void __devexit pt1_remove(struct pci_dev *pdev)
 	pt1 = pci_get_drvdata(pdev);
 	regs = pt1->regs;
 
-	kthread_stop(pt1->kthread);
+	if (pt1->kthread)
+		kthread_stop(pt1->kthread);
 	pt1_cleanup_tables(pt1);
 	pt1_cleanup_frontends(pt1);
 	pt1_disable_ram(pt1);
@@ -1043,7 +1080,6 @@ pt1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	void __iomem *regs;
 	struct pt1 *pt1;
 	struct i2c_adapter *i2c_adap;
-	struct task_struct *kthread;
 
 	ret = pci_enable_device(pdev);
 	if (ret < 0)
@@ -1139,17 +1175,8 @@ pt1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret < 0)
 		goto err_pt1_cleanup_frontends;
 
-	kthread = kthread_run(pt1_thread, pt1, "pt1");
-	if (IS_ERR(kthread)) {
-		ret = PTR_ERR(kthread);
-		goto err_pt1_cleanup_tables;
-	}
-
-	pt1->kthread = kthread;
 	return 0;
 
-err_pt1_cleanup_tables:
-	pt1_cleanup_tables(pt1);
 err_pt1_cleanup_frontends:
 	pt1_cleanup_frontends(pt1);
 err_pt1_disable_ram: