Merge branch 'patchwork' into topic/docs-next

* patchwork: (1492 commits)
  [media] cec: always check all_device_types and features
  [media] cec: poll should check if there is room in the tx queue
  [media] vivid: support monitor all mode
  [media] cec: fix test for unconfigured adapter in main message loop
  [media] cec: limit the size of the transmit queue
  [media] cec: zero unused msg part after msg->len
  [media] cec: don't set fh to NULL in CEC_TRANSMIT
  [media] cec: clear all status fields before transmit and always fill in sequence
  [media] cec: CEC_RECEIVE overwrote the timeout field
  [media] cxd2841er: Reading SNR for DVB-C added
  [media] cxd2841er: Reading BER and UCB for DVB-C added
  [media] cxd2841er: fix switch-case for DVB-C
  [media] cxd2841er: fix signal strength scale for ISDB-T
  [media] cxd2841er: adjust the dB scale for DVB-C
  [media] cxd2841er: provide signal strength for DVB-C
  [media] cxd2841er: fix BER report via DVBv5 stats API
  [media] mb86a20s: apply mask to val after checking for read failure
  [media] airspy: fix error logic during device register
  [media] s5p-cec/TODO: add TODO item
  [media] cec/TODO: drop comment about sphinx documentation
  ...

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

8 files changed, 120 insertions, 38 deletions

diff --git a/drivers/media/dvb-core/demux.h b/drivers/media/dvb-core/demux.h
index ad42252b1c66..99379c09aa7f 100644
--- a/drivers/media/dvb-core/demux.h
+++ b/drivers/media/dvb-core/demux.h
@@ -104,7 +104,7 @@ struct dmx_ts_feed {
 		   int type,
 		   enum dmx_ts_pes pes_type,
 		   size_t circular_buffer_size,
-		   struct timespec timeout);
+		   ktime_t timeout);
 	int (*start_filtering)(struct dmx_ts_feed *feed);
 	int (*stop_filtering)(struct dmx_ts_feed *feed);
 };
diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index a168cbe1c998..7b67e1dd97fd 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -556,7 +556,7 @@ static int dvb_dmxdev_start_feed(struct dmxdev *dmxdev,
 				 struct dmxdev_filter *filter,
 				 struct dmxdev_feed *feed)
 {
-	struct timespec timeout = { 0 };
+	ktime_t timeout = ktime_set(0, 0);
 	struct dmx_pes_filter_params *para = &filter->params.pes;
 	dmx_output_t otype;
 	int ret;
diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c
index b1e3a26b1431..b5b5b195ea7f 100644
--- a/drivers/media/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -123,6 +123,7 @@ struct dvb_ca_slot {
 
 /* Private CA-interface information */
 struct dvb_ca_private {
+	struct kref refcount;
 
 	/* pointer back to the public data structure */
 	struct dvb_ca_en50221 *pub;
@@ -173,6 +174,22 @@ static void dvb_ca_private_free(struct dvb_ca_private *ca)
 	kfree(ca);
 }
 
+static void dvb_ca_private_release(struct kref *ref)
+{
+	struct dvb_ca_private *ca = container_of(ref, struct dvb_ca_private, refcount);
+	dvb_ca_private_free(ca);
+}
+
+static void dvb_ca_private_get(struct dvb_ca_private *ca)
+{
+	kref_get(&ca->refcount);
+}
+
+static void dvb_ca_private_put(struct dvb_ca_private *ca)
+{
+	kref_put(&ca->refcount, dvb_ca_private_release);
+}
+
 static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca);
 static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot, u8 * ebuf, int ecount);
 static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, u8 * ebuf, int ecount);
@@ -1570,6 +1587,8 @@ static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
 	dvb_ca_en50221_thread_update_delay(ca);
 	dvb_ca_en50221_thread_wakeup(ca);
 
+	dvb_ca_private_get(ca);
+
 	return 0;
 }
 
@@ -1598,6 +1617,8 @@ static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
 
 	module_put(ca->pub->owner);
 
+	dvb_ca_private_put(ca);
+
 	return err;
 }
 
@@ -1693,6 +1714,7 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
 		ret = -ENOMEM;
 		goto exit;
 	}
+	kref_init(&ca->refcount);
 	ca->pub = pubca;
 	ca->flags = flags;
 	ca->slot_count = slot_count;
@@ -1772,6 +1794,6 @@ void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
 	for (i = 0; i < ca->slot_count; i++) {
 		dvb_ca_en50221_slot_shutdown(ca, i);
 	}
-	dvb_ca_private_free(ca);
+	dvb_ca_private_put(ca);
 	pubca->private = NULL;
 }
diff --git a/drivers/media/dvb-core/dvb_demux.c b/drivers/media/dvb-core/dvb_demux.c
index 0cc5e935166c..a0cf7b0d03e8 100644
--- a/drivers/media/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb-core/dvb_demux.c
@@ -398,28 +398,23 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
 	int dvr_done = 0;
 
 	if (dvb_demux_speedcheck) {
-		struct timespec cur_time, delta_time;
+		ktime_t cur_time;
 		u64 speed_bytes, speed_timedelta;
 
 		demux->speed_pkts_cnt++;
 
 		/* show speed every SPEED_PKTS_INTERVAL packets */
 		if (!(demux->speed_pkts_cnt % SPEED_PKTS_INTERVAL)) {
-			cur_time = current_kernel_time();
+			cur_time = ktime_get();
 
-			if (demux->speed_last_time.tv_sec != 0 &&
-					demux->speed_last_time.tv_nsec != 0) {
-				delta_time = timespec_sub(cur_time,
-						demux->speed_last_time);
+			if (ktime_to_ns(demux->speed_last_time) != 0) {
 				speed_bytes = (u64)demux->speed_pkts_cnt
 					* 188 * 8;
 				/* convert to 1024 basis */
 				speed_bytes = 1000 * div64_u64(speed_bytes,
 						1024);
-				speed_timedelta =
-					(u64)timespec_to_ns(&delta_time);
-				speed_timedelta = div64_u64(speed_timedelta,
-						1000000); /* nsec -> usec */
+				speed_timedelta = ktime_ms_delta(cur_time,
+							demux->speed_last_time);
 				printk(KERN_INFO "TS speed %llu Kbits/sec \n",
 						div64_u64(speed_bytes,
 							speed_timedelta));
@@ -666,7 +661,7 @@ out:
 
 static int dmx_ts_feed_set(struct dmx_ts_feed *ts_feed, u16 pid, int ts_type,
 			   enum dmx_ts_pes pes_type,
-			   size_t circular_buffer_size, struct timespec timeout)
+			   size_t circular_buffer_size, ktime_t timeout)
 {
 	struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;
 	struct dvb_demux *demux = feed->demux;
diff --git a/drivers/media/dvb-core/dvb_demux.h b/drivers/media/dvb-core/dvb_demux.h
index ae7fc33c3231..5ed3cab4ad28 100644
--- a/drivers/media/dvb-core/dvb_demux.h
+++ b/drivers/media/dvb-core/dvb_demux.h
@@ -83,7 +83,7 @@ struct dvb_demux_feed {
 	u8 *buffer;
 	int buffer_size;
 
-	struct timespec timeout;
+	ktime_t timeout;
 	struct dvb_demux_filter *filter;
 
 	int ts_type;
@@ -134,7 +134,7 @@ struct dvb_demux {
 
 	uint8_t *cnt_storage; /* for TS continuity check */
 
-	struct timespec speed_last_time; /* for TS speed check */
+	ktime_t speed_last_time; /* for TS speed check */
 	uint32_t speed_pkts_cnt; /* for TS speed check */
 };
 
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index c0142614c408..be99c8dbc5f8 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -99,6 +99,7 @@ MODULE_PARM_DESC(dvb_mfe_wait_time, "Wait up to <mfe_wait_time> seconds on open(
 static DEFINE_MUTEX(frontend_mutex);
 
 struct dvb_frontend_private {
+	struct kref refcount;
 
 	/* thread/frontend values */
 	struct dvb_device *dvbdev;
@@ -137,6 +138,23 @@ struct dvb_frontend_private {
 #endif
 };
 
+static void dvb_frontend_private_free(struct kref *ref)
+{
+	struct dvb_frontend_private *fepriv =
+		container_of(ref, struct dvb_frontend_private, refcount);
+	kfree(fepriv);
+}
+
+static void dvb_frontend_private_put(struct dvb_frontend_private *fepriv)
+{
+	kref_put(&fepriv->refcount, dvb_frontend_private_free);
+}
+
+static void dvb_frontend_private_get(struct dvb_frontend_private *fepriv)
+{
+	kref_get(&fepriv->refcount);
+}
+
 static void dvb_frontend_wakeup(struct dvb_frontend *fe);
 static int dtv_get_frontend(struct dvb_frontend *fe,
 			    struct dtv_frontend_properties *c,
@@ -2543,6 +2561,8 @@ static int dvb_frontend_open(struct inode *inode, struct file *file)
 		fepriv->events.eventr = fepriv->events.eventw = 0;
 	}
 
+	dvb_frontend_private_get(fepriv);
+
 	if (adapter->mfe_shared)
 		mutex_unlock (&adapter->mfe_lock);
 	return ret;
@@ -2591,6 +2611,8 @@ static int dvb_frontend_release(struct inode *inode, struct file *file)
 			fe->ops.ts_bus_ctrl(fe, 0);
 	}
 
+	dvb_frontend_private_put(fepriv);
+
 	return ret;
 }
 
@@ -2679,6 +2701,8 @@ int dvb_register_frontend(struct dvb_adapter* dvb,
 	}
 	fepriv = fe->frontend_priv;
 
+	kref_init(&fepriv->refcount);
+
 	sema_init(&fepriv->sem, 1);
 	init_waitqueue_head (&fepriv->wait_queue);
 	init_waitqueue_head (&fepriv->events.wait_queue);
@@ -2713,18 +2737,11 @@ int dvb_unregister_frontend(struct dvb_frontend* fe)
 
 	mutex_lock(&frontend_mutex);
 	dvb_frontend_stop (fe);
-	mutex_unlock(&frontend_mutex);
-
-	if (fepriv->dvbdev->users < -1)
-		wait_event(fepriv->dvbdev->wait_queue,
-				fepriv->dvbdev->users==-1);
-
-	mutex_lock(&frontend_mutex);
 	dvb_unregister_device (fepriv->dvbdev);
 
 	/* fe is invalid now */
-	kfree(fepriv);
 	mutex_unlock(&frontend_mutex);
+	dvb_frontend_private_put(fepriv);
 	return 0;
 }
 EXPORT_SYMBOL(dvb_unregister_frontend);
diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c
index ce6a711b42d4..9914f69a4a02 100644
--- a/drivers/media/dvb-core/dvb_net.c
+++ b/drivers/media/dvb-core/dvb_net.c
@@ -997,7 +997,7 @@ static int dvb_net_feed_start(struct net_device *dev)
 		netdev_dbg(dev, "start filtering\n");
 		priv->secfeed->start_filtering(priv->secfeed);
 	} else if (priv->feedtype == DVB_NET_FEEDTYPE_ULE) {
-		struct timespec timeout = { 0, 10000000 }; // 10 msec
+		ktime_t timeout = ns_to_ktime(10 * NSEC_PER_MSEC);
 
 		/* we have payloads encapsulated in TS */
 		netdev_dbg(dev, "alloc tsfeed\n");
diff --git a/drivers/media/dvb-core/dvb_ringbuffer.c b/drivers/media/dvb-core/dvb_ringbuffer.c
index 1100e98a7b1d..7df7fb3738a0 100644
--- a/drivers/media/dvb-core/dvb_ringbuffer.c
+++ b/drivers/media/dvb-core/dvb_ringbuffer.c
@@ -55,7 +55,13 @@ void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len)
 
 int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf)
 {
-	return (rbuf->pread==rbuf->pwrite);
+	/* smp_load_acquire() to load write pointer on reader side
+	 * this pairs with smp_store_release() in dvb_ringbuffer_write(),
+	 * dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset()
+	 *
+	 * for memory barriers also see Documentation/circular-buffers.txt
+	 */
+	return (rbuf->pread == smp_load_acquire(&rbuf->pwrite));
 }
 
 
@@ -64,7 +70,12 @@ ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf)
 {
 	ssize_t free;
 
-	free = rbuf->pread - rbuf->pwrite;
+	/* ACCESS_ONCE() to load read pointer on writer side
+	 * this pairs with smp_store_release() in dvb_ringbuffer_read(),
+	 * dvb_ringbuffer_read_user(), dvb_ringbuffer_flush(),
+	 * or dvb_ringbuffer_reset()
+	 */
+	free = ACCESS_ONCE(rbuf->pread) - rbuf->pwrite;
 	if (free <= 0)
 		free += rbuf->size;
 	return free-1;
@@ -76,7 +87,11 @@ ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
 {
 	ssize_t avail;
 
-	avail = rbuf->pwrite - rbuf->pread;
+	/* smp_load_acquire() to load write pointer on reader side
+	 * this pairs with smp_store_release() in dvb_ringbuffer_write(),
+	 * dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset()
+	 */
+	avail = smp_load_acquire(&rbuf->pwrite) - rbuf->pread;
 	if (avail < 0)
 		avail += rbuf->size;
 	return avail;
@@ -86,14 +101,25 @@ ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
 
 void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
 {
-	rbuf->pread = rbuf->pwrite;
+	/* dvb_ringbuffer_flush() counts as read operation
+	 * smp_load_acquire() to load write pointer
+	 * smp_store_release() to update read pointer, this ensures that the
+	 * correct pointer is visible for subsequent dvb_ringbuffer_free()
+	 * calls on other cpu cores
+	 */
+	smp_store_release(&rbuf->pread, smp_load_acquire(&rbuf->pwrite));
 	rbuf->error = 0;
 }
 EXPORT_SYMBOL(dvb_ringbuffer_flush);
 
 void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf)
 {
-	rbuf->pread = rbuf->pwrite = 0;
+	/* dvb_ringbuffer_reset() counts as read and write operation
+	 * smp_store_release() to update read pointer
+	 */
+	smp_store_release(&rbuf->pread, 0);
+	/* smp_store_release() to update write pointer */
+	smp_store_release(&rbuf->pwrite, 0);
 	rbuf->error = 0;
 }
 
@@ -119,12 +145,17 @@ ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, si
 			return -EFAULT;
 		buf += split;
 		todo -= split;
-		rbuf->pread = 0;
+		/* smp_store_release() for read pointer update to ensure
+		 * that buf is not overwritten until read is complete,
+		 * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free()
+		 */
+		smp_store_release(&rbuf->pread, 0);
 	}
 	if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
 		return -EFAULT;
 
-	rbuf->pread = (rbuf->pread + todo) % rbuf->size;
+	/* smp_store_release() to update read pointer, see above */
+	smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size);
 
 	return len;
 }
@@ -139,11 +170,16 @@ void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len)
 		memcpy(buf, rbuf->data+rbuf->pread, split);
 		buf += split;
 		todo -= split;
-		rbuf->pread = 0;
+		/* smp_store_release() for read pointer update to ensure
+		 * that buf is not overwritten until read is complete,
+		 * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free()
+		 */
+		smp_store_release(&rbuf->pread, 0);
 	}
 	memcpy(buf, rbuf->data+rbuf->pread, todo);
 
-	rbuf->pread = (rbuf->pread + todo) % rbuf->size;
+	/* smp_store_release() to update read pointer, see above */
+	smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size);
 }
 
 
@@ -158,10 +194,16 @@ ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t
 		memcpy(rbuf->data+rbuf->pwrite, buf, split);
 		buf += split;
 		todo -= split;
-		rbuf->pwrite = 0;
+		/* smp_store_release() for write pointer update to ensure that
+		 * written data is visible on other cpu cores before the pointer
+		 * update, this pairs with smp_load_acquire() in
+		 * dvb_ringbuffer_empty() or dvb_ringbuffer_avail()
+		 */
+		smp_store_release(&rbuf->pwrite, 0);
 	}
 	memcpy(rbuf->data+rbuf->pwrite, buf, todo);
-	rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
+	/* smp_store_release() for write pointer update, see above */
+	smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size);
 
 	return len;
 }
@@ -181,12 +223,18 @@ ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
 			return len - todo;
 		buf += split;
 		todo -= split;
-		rbuf->pwrite = 0;
+		/* smp_store_release() for write pointer update to ensure that
+		 * written data is visible on other cpu cores before the pointer
+		 * update, this pairs with smp_load_acquire() in
+		 * dvb_ringbuffer_empty() or dvb_ringbuffer_avail()
+		 */
+		smp_store_release(&rbuf->pwrite, 0);
 	}
 	status = copy_from_user(rbuf->data+rbuf->pwrite, buf, todo);
 	if (status)
 		return len - todo;
-	rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
+	/* smp_store_release() for write pointer update, see above */
+	smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size);
 
 	return len;
 }