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: