[PATCH v2 0/4] Improve DVB memory mapped API

[PATCH v2 0/4] Improve DVB memory mapped API

[Mauro Carvalho Chehab]

This series improve the DVB memory mapped API to allow it to
report continuity errors.

Doing it for Digital TV standards is not mandatory, as
MPEG-TS has already support for it. Yet, when trying to
discover if the discontinuity happened due to a driver problem
or due to userspace troubles can be tricky.

So, this patch series add two fields at the struct used by
DMX_DQBUF (struct dmx_buffer):

- count: a simple monotonic uint32_t counter;
- flags: a bitmap field that lets the DVB core to report if
  it detects an error.

There are already some logic inside the demux code that checks
for discontinuity errors while receiving data. Make them to
update the flags.

Somehow, some changes I made while testing the DVB API never
made upstream: Arnd had to write some fixes for it to be built
and parts of the conditional support had a reverted logic.

patch 1 actually addresses an old issue at the DVB demux API:
if an ioctl fails due to invalid parameters, or if an ioctl
doesn't exist, it returns the same error code (-EINVAL).
The patch changes the latter to -ENOTTY>

patch 2 fixes the DMA mmap support, that was merged lacking
a fix that got lost. I ended by rewriting the code, making it
simpler.

patch 3 adds count/flags to mmap API;

patch 4 makes the DVB core to update count and flags.

All those patches are at:
	https://git.linuxtv.org/mchehab/experimental.git/log/?h=dvb-mmap-v3

The v4l-utils code, updated to use the mmap API, is at:
	https://git.linuxtv.org/mchehab/experimental-v4l-utils.git/log/?h=dvb-mmap-v2

Please notice that the API is experimental, and may still change
until we release the final version of Kernel 4.16.

Have fun,
Mauro

Mauro Carvalho Chehab (4):
  media: dmxdev: fix error code for invalid ioctls
  media: dmxdev: Fix the logic that enables DMA mmap support
  media: dvb: add continuity error indicators for memory mapped buffers
  media: dvb: update buffer mmaped flags and frame counter

 Documentation/media/dmx.h.rst.exceptions  |  14 ++--
 Documentation/media/uapi/dvb/dmx-qbuf.rst |   7 +-
 drivers/media/dvb-core/dmxdev.c           |  98 +++++++++++++++-----------
 drivers/media/dvb-core/dvb_demux.c        | 113 +++++++++++++++++++-----------
 drivers/media/dvb-core/dvb_net.c          |   5 +-
 drivers/media/dvb-core/dvb_vb2.c          |  31 +++++---
 include/media/demux.h                     |  21 ++++--
 include/media/dmxdev.h                    |   2 +
 include/media/dvb_demux.h                 |   4 ++
 include/media/dvb_vb2.h                   |  18 ++++-
 include/uapi/linux/dvb/dmx.h              |  35 +++++++++
 11 files changed, 242 insertions(+), 106 deletions(-)

-- 
2.14.3

[PATCH v2 1/4] media: dmxdev: fix error code for invalid ioctls

[Mauro Carvalho Chehab]

Returning -EINVAL when an ioctl is not implemented is a very
bad idea, as it is hard to distinguish from other error
contitions that an ioctl could lead. Replace it by its
right error code: -ENOTTY.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 drivers/media/dvb-core/dmxdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 51676c7ad118..15847b64698b 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -1160,7 +1160,7 @@ static int dvb_demux_do_ioctl(struct file *file,
 		break;
 #endif
 	default:
-		ret = -EINVAL;
+		ret = -ENOTTY;
 		break;
 	}
 	mutex_unlock(&dmxdev->mutex);
-- 
2.14.3

[PATCH v2 2/4] media: dmxdev: Fix the logic that enables DMA mmap support

[Mauro Carvalho Chehab]

Some conditions required for DVB mmap support to work are reversed.
Also, the logic is not too clear.

So, improve the logic, making it easier to be handled.

PS.: I'm pretty sure that I fixed it while testing, but, somehow,
the change got lost.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 drivers/media/dvb-core/dmxdev.c | 76 +++++++++++++++++++++++------------------
 include/media/dmxdev.h          |  2 ++
 2 files changed, 44 insertions(+), 34 deletions(-)

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 15847b64698b..ad349fe26aa2 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -128,11 +128,7 @@ static int dvb_dvr_open(struct inode *inode, struct file *file)
 	struct dvb_device *dvbdev = file->private_data;
 	struct dmxdev *dmxdev = dvbdev->priv;
 	struct dmx_frontend *front;
-#ifndef CONFIG_DVB_MMAP
 	bool need_ringbuffer = false;
-#else
-	const bool need_ringbuffer = true;
-#endif
 
 	dprintk("%s\n", __func__);
 
@@ -144,17 +140,31 @@ static int dvb_dvr_open(struct inode *inode, struct file *file)
 		return -ENODEV;
 	}
 
-#ifndef CONFIG_DVB_MMAP
+	dmxdev->may_do_mmap = 0;
+
+	/*
+	 * The logic here is a little tricky due to the ifdef.
+	 *
+	 * The ringbuffer is used for both read and mmap.
+	 *
+	 * It is not needed, however, on two situations:
+	 * 	- Write devices (access with O_WRONLY);
+	 *	- For duplex device nodes, opened with O_RDWR.
+	 */
+
 	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
 		need_ringbuffer = true;
-#else
-	if ((file->f_flags & O_ACCMODE) == O_RDWR) {
+	else if ((file->f_flags & O_ACCMODE) == O_RDWR) {
 		if (!(dmxdev->capabilities & DMXDEV_CAP_DUPLEX)) {
+#ifdef CONFIG_DVB_MMAP
+			dmxdev->may_do_mmap = 1;
+			need_ringbuffer = true;
+#else
 			mutex_unlock(&dmxdev->mutex);
 			return -EOPNOTSUPP;
+#endif
 		}
 	}
-#endif
 
 	if (need_ringbuffer) {
 		void *mem;
@@ -169,8 +179,9 @@ static int dvb_dvr_open(struct inode *inode, struct file *file)
 			return -ENOMEM;
 		}
 		dvb_ringbuffer_init(&dmxdev->dvr_buffer, mem, DVR_BUFFER_SIZE);
-		dvb_vb2_init(&dmxdev->dvr_vb2_ctx, "dvr",
-			     file->f_flags & O_NONBLOCK);
+		if (dmxdev->may_do_mmap)
+			dvb_vb2_init(&dmxdev->dvr_vb2_ctx, "dvr",
+				     file->f_flags & O_NONBLOCK);
 		dvbdev->readers--;
 	}
 
@@ -200,11 +211,6 @@ static int dvb_dvr_release(struct inode *inode, struct file *file)
 {
 	struct dvb_device *dvbdev = file->private_data;
 	struct dmxdev *dmxdev = dvbdev->priv;
-#ifndef CONFIG_DVB_MMAP
-	bool need_ringbuffer = false;
-#else
-	const bool need_ringbuffer = true;
-#endif
 
 	mutex_lock(&dmxdev->mutex);
 
@@ -213,15 +219,14 @@ static int dvb_dvr_release(struct inode *inode, struct file *file)
 		dmxdev->demux->connect_frontend(dmxdev->demux,
 						dmxdev->dvr_orig_fe);
 	}
-#ifndef CONFIG_DVB_MMAP
-	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
-		need_ringbuffer = true;
-#endif
 
-	if (need_ringbuffer) {
-		if (dvb_vb2_is_streaming(&dmxdev->dvr_vb2_ctx))
-			dvb_vb2_stream_off(&dmxdev->dvr_vb2_ctx);
-		dvb_vb2_release(&dmxdev->dvr_vb2_ctx);
+	if (((file->f_flags & O_ACCMODE) == O_RDONLY) ||
+	    dmxdev->may_do_mmap) {
+		if (dmxdev->may_do_mmap) {
+			if (dvb_vb2_is_streaming(&dmxdev->dvr_vb2_ctx))
+				dvb_vb2_stream_off(&dmxdev->dvr_vb2_ctx);
+			dvb_vb2_release(&dmxdev->dvr_vb2_ctx);
+		}
 		dvbdev->readers++;
 		if (dmxdev->dvr_buffer.data) {
 			void *mem = dmxdev->dvr_buffer.data;
@@ -802,6 +807,12 @@ static int dvb_demux_open(struct inode *inode, struct file *file)
 	mutex_init(&dmxdevfilter->mutex);
 	file->private_data = dmxdevfilter;
 
+#ifdef CONFIG_DVB_MMAP
+	dmxdev->may_do_mmap = 1;
+#else
+	dmxdev->may_do_mmap = 0;
+#endif
+
 	dvb_ringbuffer_init(&dmxdevfilter->buffer, NULL, 8192);
 	dvb_vb2_init(&dmxdevfilter->vb2_ctx, "demux_filter",
 		     file->f_flags & O_NONBLOCK);
@@ -1206,6 +1217,9 @@ static int dvb_demux_mmap(struct file *file, struct vm_area_struct *vma)
 	struct dmxdev *dmxdev = dmxdevfilter->dev;
 	int ret;
 
+	if (!dmxdev->may_do_mmap)
+		return -EOPNOTSUPP;
+
 	if (mutex_lock_interruptible(&dmxdev->mutex))
 		return -ERESTARTSYS;
 
@@ -1323,12 +1337,6 @@ static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)
 	struct dmxdev *dmxdev = dvbdev->priv;
 	unsigned int mask = 0;
 
-#ifndef CONFIG_DVB_MMAP
-	bool need_ringbuffer = false;
-#else
-	const bool need_ringbuffer = true;
-#endif
-
 	dprintk("%s\n", __func__);
 
 	if (dmxdev->exit)
@@ -1338,11 +1346,8 @@ static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)
 
 	poll_wait(file, &dmxdev->dvr_buffer.queue, wait);
 
-#ifndef CONFIG_DVB_MMAP
-	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
-		need_ringbuffer = true;
-#endif
-	if (need_ringbuffer) {
+	if (((file->f_flags & O_ACCMODE) == O_RDONLY) ||
+	    dmxdev->may_do_mmap) {
 		if (dmxdev->dvr_buffer.error)
 			mask |= (POLLIN | POLLRDNORM | POLLPRI | POLLERR);
 
@@ -1361,6 +1366,9 @@ static int dvb_dvr_mmap(struct file *file, struct vm_area_struct *vma)
 	struct dmxdev *dmxdev = dvbdev->priv;
 	int ret;
 
+	if (!dmxdev->may_do_mmap)
+		return -EOPNOTSUPP;
+
 	if (dmxdev->exit)
 		return -ENODEV;
 
diff --git a/include/media/dmxdev.h b/include/media/dmxdev.h
index 2f5cb2c7b6a7..baafa3b8aca4 100644
--- a/include/media/dmxdev.h
+++ b/include/media/dmxdev.h
@@ -163,6 +163,7 @@ struct dmxdev_filter {
  * @demux:		pointer to &struct dmx_demux.
  * @filternum:		number of filters.
  * @capabilities:	demux capabilities as defined by &enum dmx_demux_caps.
+ * @may_do_mmap:	flag used to indicate if the device may do mmap.
  * @exit:		flag to indicate that the demux is being released.
  * @dvr_orig_fe:	pointer to &struct dmx_frontend.
  * @dvr_buffer:		embedded &struct dvb_ringbuffer for DVB output.
@@ -180,6 +181,7 @@ struct dmxdev {
 	int filternum;
 	int capabilities;
 
+	unsigned int may_do_mmap:1;
 	unsigned int exit:1;
 #define DMXDEV_CAP_DUPLEX 1
 	struct dmx_frontend *dvr_orig_fe;
-- 
2.14.3

[PATCH v2 3/4] media: dvb: add continuity error indicators for memory mapped buffers

[Mauro Carvalho Chehab]

While userspace can detect discontinuity errors, it is useful to
also let Kernelspace reporting discontinuity, as it can help to
identify if the data loss happened either at Kernel or userspace side.

Update documentation accordingly.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 Documentation/media/dmx.h.rst.exceptions  | 14 +++++++++----
 Documentation/media/uapi/dvb/dmx-qbuf.rst |  7 ++++---
 include/uapi/linux/dvb/dmx.h              | 35 +++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 7 deletions(-)

diff --git a/Documentation/media/dmx.h.rst.exceptions b/Documentation/media/dmx.h.rst.exceptions
index 63f55a9ae2b1..a8c4239ed95b 100644
--- a/Documentation/media/dmx.h.rst.exceptions
+++ b/Documentation/media/dmx.h.rst.exceptions
@@ -50,9 +50,15 @@ replace typedef dmx_filter_t :c:type:`dmx_filter`
 replace typedef dmx_pes_type_t :c:type:`dmx_pes_type`
 replace typedef dmx_input_t :c:type:`dmx_input`
 
-ignore symbol DMX_OUT_DECODER
-ignore symbol DMX_OUT_TAP
-ignore symbol DMX_OUT_TS_TAP
-ignore symbol DMX_OUT_TSDEMUX_TAP
+replace symbol DMX_BUFFER_FLAG_HAD_CRC32_DISCARD :c:type:`dmx_buffer_flags`
+replace	symbol DMX_BUFFER_FLAG_TEI :c:type:`dmx_buffer_flags`
+replace	symbol DMX_BUFFER_PKT_COUNTER_MISMATCH :c:type:`dmx_buffer_flags`
+replace	symbol DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED :c:type:`dmx_buffer_flags`
+replace	symbol DMX_BUFFER_FLAG_DISCONTINUITY_INDICATOR :c:type:`dmx_buffer_flags`
+
+replace symbol DMX_OUT_DECODER :c:type:`dmx_output`
+replace symbol DMX_OUT_TAP :c:type:`dmx_output`
+replace symbol DMX_OUT_TS_TAP :c:type:`dmx_output`
+replace symbol DMX_OUT_TSDEMUX_TAP :c:type:`dmx_output`
 
 replace ioctl DMX_DQBUF dmx_qbuf
diff --git a/Documentation/media/uapi/dvb/dmx-qbuf.rst b/Documentation/media/uapi/dvb/dmx-qbuf.rst
index b48c4931658e..be5a4c6f1904 100644
--- a/Documentation/media/uapi/dvb/dmx-qbuf.rst
+++ b/Documentation/media/uapi/dvb/dmx-qbuf.rst
@@ -51,9 +51,10 @@ out to disk. Buffers remain locked until dequeued, until the
 the device is closed.
 
 Applications call the ``DMX_DQBUF`` ioctl to dequeue a filled
-(capturing) buffer from the driver's outgoing queue. They just set the ``reserved`` field array to zero. When ``DMX_DQBUF`` is called with a
-pointer to this structure, the driver fills the remaining fields or
-returns an error code.
+(capturing) buffer from the driver's outgoing queue.
+They just set the ``index`` field withe the buffer ID to be queued.
+When ``DMX_DQBUF`` is called with a pointer to struct :c:type:`dmx_buffer`,
+the driver fills the remaining fields or returns an error code.
 
 By default ``DMX_DQBUF`` blocks when no buffer is in the outgoing
 queue. When the ``O_NONBLOCK`` flag was given to the
diff --git a/include/uapi/linux/dvb/dmx.h b/include/uapi/linux/dvb/dmx.h
index 5f3c5a918f00..a656b7a66f6e 100644
--- a/include/uapi/linux/dvb/dmx.h
+++ b/include/uapi/linux/dvb/dmx.h
@@ -211,6 +211,32 @@ struct dmx_stc {
 	__u64 stc;
 };
 
+/**
+ * enum dmx_buffer_flags - DMX memory-mapped buffer flags
+ *
+ * @DMX_BUFFER_FLAG_HAD_CRC32_DISCARD:
+ *	Indicates that the Kernel discarded one or more frames due to wrong
+ *	CRC32 checksum.
+ * @DMX_BUFFER_FLAG_TEI:
+ * 	Indicates that the Kernel has detected a Transport Error indicator
+ *	(TEI) on a filtered pid.
+ * @DMX_BUFFER_PKT_COUNTER_MISMATCH:
+ * 	Indicates that the Kernel has detected a packet counter mismatch
+ *	on a filtered pid.
+ * @DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED:
+ * 	Indicates that the Kernel has detected one or more frame discontinuity.
+ * @DMX_BUFFER_FLAG_DISCONTINUITY_INDICATOR:
+ * 	Received at least one packet with a frame discontinuity indicator.
+ */
+
+enum dmx_buffer_flags {
+	DMX_BUFFER_FLAG_HAD_CRC32_DISCARD		= 1 << 0,
+	DMX_BUFFER_FLAG_TEI				= 1 << 1,
+	DMX_BUFFER_PKT_COUNTER_MISMATCH			= 1 << 2,
+	DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED		= 1 << 3,
+	DMX_BUFFER_FLAG_DISCONTINUITY_INDICATOR		= 1 << 4,
+};
+
 /**
  * struct dmx_buffer - dmx buffer info
  *
@@ -220,15 +246,24 @@ struct dmx_stc {
  *		offset from the start of the device memory for this plane,
  *		(or a "cookie" that should be passed to mmap() as offset)
  * @length:	size in bytes of the buffer
+ * @flags:	bit array of buffer flags as defined by &enum dmx_buffer_flags.
+ *		Filled only at &DMX_DQBUF.
+ * @count:	monotonic counter for filled buffers. Helps to identify
+ *		data stream loses. Filled only at &DMX_DQBUF.
  *
  * Contains data exchanged by application and driver using one of the streaming
  * I/O methods.
+ *
+ * Please notice that, for &DMX_QBUF, only @index should be filled.
+ * On &DMX_DQBUF calls, all fields will be filled by the Kernel.
  */
 struct dmx_buffer {
 	__u32			index;
 	__u32			bytesused;
 	__u32			offset;
 	__u32			length;
+	__u32			flags;
+	__u32			count;
 };
 
 /**
-- 
2.14.3

[PATCH v2 4/4] media: dvb: update buffer mmaped flags and frame counter

[Mauro Carvalho Chehab]

Now that we have support for a buffer counter and for
error flags, update them at DMX_DQBUF.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
 drivers/media/dvb-core/dmxdev.c    |  24 +++++---
 drivers/media/dvb-core/dvb_demux.c | 113 ++++++++++++++++++++++++-------------
 drivers/media/dvb-core/dvb_net.c   |   5 +-
 drivers/media/dvb-core/dvb_vb2.c   |  31 +++++++---
 include/media/demux.h              |  21 +++++--
 include/media/dvb_demux.h          |   4 ++
 include/media/dvb_vb2.h            |  18 +++++-
 7 files changed, 150 insertions(+), 66 deletions(-)

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index ad349fe26aa2..34f54d443d08 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -385,7 +385,8 @@ static void dvb_dmxdev_filter_timer(struct dmxdev_filter *dmxdevfilter)
 
 static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
 				       const u8 *buffer2, size_t buffer2_len,
-				       struct dmx_section_filter *filter)
+				       struct dmx_section_filter *filter,
+				       u32 *buffer_flags)
 {
 	struct dmxdev_filter *dmxdevfilter = filter->priv;
 	int ret;
@@ -404,10 +405,12 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
 	dprintk("section callback %*ph\n", 6, buffer1);
 	if (dvb_vb2_is_streaming(&dmxdevfilter->vb2_ctx)) {
 		ret = dvb_vb2_fill_buffer(&dmxdevfilter->vb2_ctx,
-					  buffer1, buffer1_len);
+					  buffer1, buffer1_len,
+					  buffer_flags);
 		if (ret == buffer1_len)
 			ret = dvb_vb2_fill_buffer(&dmxdevfilter->vb2_ctx,
-						  buffer2, buffer2_len);
+						  buffer2, buffer2_len,
+						  buffer_flags);
 	} else {
 		ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer,
 					      buffer1, buffer1_len);
@@ -427,7 +430,8 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
 
 static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
 				  const u8 *buffer2, size_t buffer2_len,
-				  struct dmx_ts_feed *feed)
+				  struct dmx_ts_feed *feed,
+				  u32 *buffer_flags)
 {
 	struct dmxdev_filter *dmxdevfilter = feed->priv;
 	struct dvb_ringbuffer *buffer;
@@ -456,9 +460,11 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
 	}
 
 	if (dvb_vb2_is_streaming(ctx)) {
-		ret = dvb_vb2_fill_buffer(ctx, buffer1, buffer1_len);
+		ret = dvb_vb2_fill_buffer(ctx, buffer1, buffer1_len,
+					  buffer_flags);
 		if (ret == buffer1_len)
-			ret = dvb_vb2_fill_buffer(ctx, buffer2, buffer2_len);
+			ret = dvb_vb2_fill_buffer(ctx, buffer2, buffer2_len,
+						  buffer_flags);
 	} else {
 		if (buffer->error) {
 			spin_unlock(&dmxdevfilter->dev->lock);
@@ -1218,7 +1224,7 @@ static int dvb_demux_mmap(struct file *file, struct vm_area_struct *vma)
 	int ret;
 
 	if (!dmxdev->may_do_mmap)
-		return -EOPNOTSUPP;
+		return -ENOTTY;
 
 	if (mutex_lock_interruptible(&dmxdev->mutex))
 		return -ERESTARTSYS;
@@ -1318,7 +1324,7 @@ static int dvb_dvr_do_ioctl(struct file *file,
 		break;
 #endif
 	default:
-		ret = -EINVAL;
+		ret = -ENOTTY;
 		break;
 	}
 	mutex_unlock(&dmxdev->mutex);
@@ -1367,7 +1373,7 @@ static int dvb_dvr_mmap(struct file *file, struct vm_area_struct *vma)
 	int ret;
 
 	if (!dmxdev->may_do_mmap)
-		return -EOPNOTSUPP;
+		return -ENOTTY;
 
 	if (dmxdev->exit)
 		return -ENODEV;
diff --git a/drivers/media/dvb-core/dvb_demux.c b/drivers/media/dvb-core/dvb_demux.c
index 210eed0269b0..86afdec13922 100644
--- a/drivers/media/dvb-core/dvb_demux.c
+++ b/drivers/media/dvb-core/dvb_demux.c
@@ -55,6 +55,17 @@ MODULE_PARM_DESC(dvb_demux_feed_err_pkts,
 		dprintk(x);				\
 } while (0)
 
+#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
+#  define dprintk_sect_loss(x...) dprintk(x)
+#else
+#  define dprintk_sect_loss(x...)
+#endif
+
+#define set_buf_flags(__feed, __flag)			\
+	do {						\
+		(__feed)->buffer_flags |= (__flag);	\
+	} while (0)
+
 /******************************************************************************
  * static inlined helper functions
  ******************************************************************************/
@@ -104,31 +115,30 @@ static inline int dvb_dmx_swfilter_payload(struct dvb_demux_feed *feed,
 {
 	int count = payload(buf);
 	int p;
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
 	int ccok;
 	u8 cc;
-#endif
 
 	if (count == 0)
 		return -1;
 
 	p = 188 - count;
 
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
 	cc = buf[3] & 0x0f;
 	ccok = ((feed->cc + 1) & 0x0f) == cc;
 	feed->cc = cc;
-	if (!ccok)
-		dprintk("missed packet: %d instead of %d!\n",
-			cc, (feed->cc + 1) & 0x0f);
-#endif
+	if (!ccok) {
+		set_buf_flags(feed, DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+		dprintk_sect_loss("missed packet: %d instead of %d!\n",
+				  cc, (feed->cc + 1) & 0x0f);
+	}
 
 	if (buf[1] & 0x40)	// PUSI ?
 		feed->peslen = 0xfffa;
 
 	feed->peslen += count;
 
-	return feed->cb.ts(&buf[p], count, NULL, 0, &feed->feed.ts);
+	return feed->cb.ts(&buf[p], count, NULL, 0, &feed->feed.ts,
+			   &feed->buffer_flags);
 }
 
 static int dvb_dmx_swfilter_sectionfilter(struct dvb_demux_feed *feed,
@@ -150,7 +160,7 @@ static int dvb_dmx_swfilter_sectionfilter(struct dvb_demux_feed *feed,
 		return 0;
 
 	return feed->cb.sec(feed->feed.sec.secbuf, feed->feed.sec.seclen,
-			    NULL, 0, &f->filter);
+			    NULL, 0, &f->filter, &feed->buffer_flags);
 }
 
 static inline int dvb_dmx_swfilter_section_feed(struct dvb_demux_feed *feed)
@@ -169,8 +179,10 @@ static inline int dvb_dmx_swfilter_section_feed(struct dvb_demux_feed *feed)
 	if (sec->check_crc) {
 		section_syntax_indicator = ((sec->secbuf[1] & 0x80) != 0);
 		if (section_syntax_indicator &&
-		    demux->check_crc32(feed, sec->secbuf, sec->seclen))
+		    demux->check_crc32(feed, sec->secbuf, sec->seclen)) {
+			set_buf_flags(feed, DMX_BUFFER_FLAG_HAD_CRC32_DISCARD);
 			return -1;
+		}
 	}
 
 	do {
@@ -187,7 +199,6 @@ static void dvb_dmx_swfilter_section_new(struct dvb_demux_feed *feed)
 {
 	struct dmx_section_feed *sec = &feed->feed.sec;
 
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
 	if (sec->secbufp < sec->tsfeedp) {
 		int n = sec->tsfeedp - sec->secbufp;
 
@@ -197,12 +208,13 @@ static void dvb_dmx_swfilter_section_new(struct dvb_demux_feed *feed)
 		 * but just first and last.
 		 */
 		if (sec->secbuf[0] != 0xff || sec->secbuf[n - 1] != 0xff) {
-			dprintk("section ts padding loss: %d/%d\n",
-			       n, sec->tsfeedp);
-			dprintk("pad data: %*ph\n", n, sec->secbuf);
+			set_buf_flags(feed,
+				      DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+			dprintk_sect_loss("section ts padding loss: %d/%d\n",
+					  n, sec->tsfeedp);
+			dprintk_sect_loss("pad data: %*ph\n", n, sec->secbuf);
 		}
 	}
-#endif
 
 	sec->tsfeedp = sec->secbufp = sec->seclen = 0;
 	sec->secbuf = sec->secbuf_base;
@@ -237,11 +249,10 @@ static int dvb_dmx_swfilter_section_copy_dump(struct dvb_demux_feed *feed,
 		return 0;
 
 	if (sec->tsfeedp + len > DMX_MAX_SECFEED_SIZE) {
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
-		dprintk("section buffer full loss: %d/%d\n",
-			sec->tsfeedp + len - DMX_MAX_SECFEED_SIZE,
-			DMX_MAX_SECFEED_SIZE);
-#endif
+		set_buf_flags(feed, DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+		dprintk_sect_loss("section buffer full loss: %d/%d\n",
+				  sec->tsfeedp + len - DMX_MAX_SECFEED_SIZE,
+				  DMX_MAX_SECFEED_SIZE);
 		len = DMX_MAX_SECFEED_SIZE - sec->tsfeedp;
 	}
 
@@ -269,12 +280,13 @@ static int dvb_dmx_swfilter_section_copy_dump(struct dvb_demux_feed *feed,
 		sec->seclen = seclen;
 		sec->crc_val = ~0;
 		/* dump [secbuf .. secbuf+seclen) */
-		if (feed->pusi_seen)
+		if (feed->pusi_seen) {
 			dvb_dmx_swfilter_section_feed(feed);
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
-		else
-			dprintk("pusi not seen, discarding section data\n");
-#endif
+		} else {
+			set_buf_flags(feed,
+				      DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+			dprintk_sect_loss("pusi not seen, discarding section data\n");
+		}
 		sec->secbufp += seclen;	/* secbufp and secbuf moving together is */
 		sec->secbuf += seclen;	/* redundant but saves pointer arithmetic */
 	}
@@ -307,18 +319,22 @@ static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
 	}
 
 	if (!ccok || dc_i) {
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
-		if (dc_i)
-			dprintk("%d frame with disconnect indicator\n",
+		if (dc_i) {
+			set_buf_flags(feed,
+				      DMX_BUFFER_FLAG_DISCONTINUITY_INDICATOR);
+			dprintk_sect_loss("%d frame with disconnect indicator\n",
 				cc);
-		else
-			dprintk("discontinuity: %d instead of %d. %d bytes lost\n",
+		} else {
+			set_buf_flags(feed,
+				      DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+			dprintk_sect_loss("discontinuity: %d instead of %d. %d bytes lost\n",
 				cc, (feed->cc + 1) & 0x0f, count + 4);
+		}
 		/*
-		 * those bytes under sume circumstances will again be reported
+		 * those bytes under some circumstances will again be reported
 		 * in the following dvb_dmx_swfilter_section_new
 		 */
-#endif
+
 		/*
 		 * Discontinuity detected. Reset pusi_seen to
 		 * stop feeding of suspicious data until next PUSI=1 arrives
@@ -326,6 +342,7 @@ static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
 		 * FIXME: does it make sense if the MPEG-TS is the one
 		 *	reporting discontinuity?
 		 */
+
 		feed->pusi_seen = false;
 		dvb_dmx_swfilter_section_new(feed);
 	}
@@ -346,10 +363,11 @@ static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
 			dvb_dmx_swfilter_section_copy_dump(feed, after,
 							   after_len);
 		}
-#ifdef CONFIG_DVB_DEMUX_SECTION_LOSS_LOG
-		else if (count > 0)
-			dprintk("PUSI=1 but %d bytes lost\n", count);
-#endif
+		else if (count > 0) {
+			set_buf_flags(feed,
+				      DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
+			dprintk_sect_loss("PUSI=1 but %d bytes lost\n", count);
+		}
 	} else {
 		/* PUSI=0 (is not set), no section boundary */
 		dvb_dmx_swfilter_section_copy_dump(feed, &buf[p], count);
@@ -369,7 +387,8 @@ static inline void dvb_dmx_swfilter_packet_type(struct dvb_demux_feed *feed,
 			if (feed->ts_type & TS_PAYLOAD_ONLY)
 				dvb_dmx_swfilter_payload(feed, buf);
 			else
-				feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts);
+				feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts,
+					    &feed->buffer_flags);
 		}
 		/* Used only on full-featured devices */
 		if (feed->ts_type & TS_DECODER)
@@ -430,6 +449,11 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
 	}
 
 	if (buf[1] & 0x80) {
+		list_for_each_entry(feed, &demux->feed_list, list_head) {
+			if ((feed->pid != pid) && (feed->pid != 0x2000))
+				continue;
+			set_buf_flags(feed, DMX_BUFFER_FLAG_TEI);
+		}
 		dprintk_tscheck("TEI detected. PID=0x%x data1=0x%x\n",
 				pid, buf[1]);
 		/* data in this packet can't be trusted - drop it unless
@@ -445,6 +469,13 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
 						(demux->cnt_storage[pid] + 1) & 0xf;
 
 				if ((buf[3] & 0xf) != demux->cnt_storage[pid]) {
+					list_for_each_entry(feed, &demux->feed_list, list_head) {
+						if ((feed->pid != pid) && (feed->pid != 0x2000))
+							continue;
+						set_buf_flags(feed,
+							      DMX_BUFFER_PKT_COUNTER_MISMATCH);
+					}
+
 					dprintk_tscheck("TS packet counter mismatch. PID=0x%x expected 0x%x got 0x%x\n",
 							pid, demux->cnt_storage[pid],
 							buf[3] & 0xf);
@@ -466,7 +497,8 @@ static void dvb_dmx_swfilter_packet(struct dvb_demux *demux, const u8 *buf)
 		if (feed->pid == pid)
 			dvb_dmx_swfilter_packet_type(feed, buf);
 		else if (feed->pid == 0x2000)
-			feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts);
+			feed->cb.ts(buf, 188, NULL, 0, &feed->feed.ts,
+				    &feed->buffer_flags);
 	}
 }
 
@@ -585,7 +617,8 @@ void dvb_dmx_swfilter_raw(struct dvb_demux *demux, const u8 *buf, size_t count)
 
 	spin_lock_irqsave(&demux->lock, flags);
 
-	demux->feed->cb.ts(buf, count, NULL, 0, &demux->feed->feed.ts);
+	demux->feed->cb.ts(buf, count, NULL, 0, &demux->feed->feed.ts,
+			   &demux->feed->buffer_flags);
 
 	spin_unlock_irqrestore(&demux->lock, flags);
 }
@@ -785,6 +818,7 @@ static int dvbdmx_allocate_ts_feed(struct dmx_demux *dmx,
 	feed->demux = demux;
 	feed->pid = 0xffff;
 	feed->peslen = 0xfffa;
+	feed->buffer_flags = 0;
 
 	(*ts_feed) = &feed->feed.ts;
 	(*ts_feed)->parent = dmx;
@@ -1042,6 +1076,7 @@ static int dvbdmx_allocate_section_feed(struct dmx_demux *demux,
 	dvbdmxfeed->cb.sec = callback;
 	dvbdmxfeed->demux = dvbdmx;
 	dvbdmxfeed->pid = 0xffff;
+	dvbdmxfeed->buffer_flags = 0;
 	dvbdmxfeed->feed.sec.secbuf = dvbdmxfeed->feed.sec.secbuf_base;
 	dvbdmxfeed->feed.sec.secbufp = dvbdmxfeed->feed.sec.seclen = 0;
 	dvbdmxfeed->feed.sec.tsfeedp = 0;
diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c
index b6c7eec863b9..ba39f9942e1d 100644
--- a/drivers/media/dvb-core/dvb_net.c
+++ b/drivers/media/dvb-core/dvb_net.c
@@ -883,7 +883,8 @@ static void dvb_net_ule(struct net_device *dev, const u8 *buf, size_t buf_len)
 
 static int dvb_net_ts_callback(const u8 *buffer1, size_t buffer1_len,
 			       const u8 *buffer2, size_t buffer2_len,
-			       struct dmx_ts_feed *feed)
+			       struct dmx_ts_feed *feed,
+			       u32 *buffer_flags)
 {
 	struct net_device *dev = feed->priv;
 
@@ -992,7 +993,7 @@ static void dvb_net_sec(struct net_device *dev,
 
 static int dvb_net_sec_callback(const u8 *buffer1, size_t buffer1_len,
 		 const u8 *buffer2, size_t buffer2_len,
-		 struct dmx_section_filter *filter)
+		 struct dmx_section_filter *filter, u32 *buffer_flags)
 {
 	struct net_device *dev = filter->priv;
 
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index 889abf9becd8..09993e9243f7 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -256,7 +256,8 @@ int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx)
 }
 
 int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
-			const unsigned char *src, int len)
+			const unsigned char *src, int len,
+			enum dmx_buffer_flags *buffer_flags)
 {
 	unsigned long flags = 0;
 	void *vbuf = NULL;
@@ -264,15 +265,17 @@ int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
 	unsigned char *psrc = (unsigned char *)src;
 	int ll = 0;
 
-	dprintk(3, "[%s] %d bytes are rcvd\n", ctx->name, len);
-	if (!src) {
-		dprintk(3, "[%s]:NULL pointer src\n", ctx->name);
-		/**normal case: This func is called twice from demux driver
-		 * once with valid src pointer, second time with NULL pointer
-		 */
+	/*
+	 * normal case: This func is called twice from demux driver
+	 * one with valid src pointer, second time with NULL pointer
+	 */
+	if (!src || !len)
 		return 0;
-	}
 	spin_lock_irqsave(&ctx->slock, flags);
+	if (buffer_flags && *buffer_flags) {
+		ctx->flags |= *buffer_flags;
+		*buffer_flags = 0;
+	}
 	while (todo) {
 		if (!ctx->buf) {
 			if (list_empty(&ctx->dvb_q)) {
@@ -395,6 +398,7 @@ int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 
 int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 {
+	unsigned long flags;
 	int ret;
 
 	ret = vb2_core_dqbuf(&ctx->vb_q, &b->index, b, ctx->nonblocking);
@@ -402,7 +406,16 @@ int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 		dprintk(1, "[%s] errno=%d\n", ctx->name, ret);
 		return ret;
 	}
-	dprintk(5, "[%s] index=%d\n", ctx->name, b->index);
+
+	spin_lock_irqsave(&ctx->slock, flags);
+	b->count = ctx->count++;
+	b->flags = ctx->flags;
+	ctx->flags = 0;
+	spin_unlock_irqrestore(&ctx->slock, flags);
+
+	dprintk(5, "[%s] index=%d, count=%d, flags=%d\n",
+		ctx->name, b->index, ctx->count, b->flags);
+
 
 	return 0;
 }
diff --git a/include/media/demux.h b/include/media/demux.h
index c4df6cee48e6..d58c43f64d55 100644
--- a/include/media/demux.h
+++ b/include/media/demux.h
@@ -117,7 +117,7 @@ struct dmx_ts_feed {
  *		  specified by @filter_value that will be used on the filter
  *		  match logic.
  * @filter_mode:  Contains a 16 bytes (128 bits) filter mode.
- * @parent:	  Pointer to struct dmx_section_feed.
+ * @parent:	  Back-pointer to struct dmx_section_feed.
  * @priv:	  Pointer to private data of the API client.
  *
  *
@@ -130,8 +130,9 @@ struct dmx_section_filter {
 	u8 filter_value[DMX_MAX_FILTER_SIZE];
 	u8 filter_mask[DMX_MAX_FILTER_SIZE];
 	u8 filter_mode[DMX_MAX_FILTER_SIZE];
-	struct dmx_section_feed *parent; /* Back-pointer */
-	void *priv; /* Pointer to private data of the API client */
+	struct dmx_section_feed *parent;
+
+	void *priv;
 };
 
 /**
@@ -193,6 +194,10 @@ struct dmx_section_feed {
  * @buffer2:		Pointer to the tail of the filtered TS packets, or NULL.
  * @buffer2_length:	Length of the TS data in buffer2.
  * @source:		Indicates which TS feed is the source of the callback.
+ * @buffer_flags:	Address where buffer flags are stored. Those are
+ * 			used to report discontinuity users via DVB
+ *			memory mapped API, as defined by
+ *			&enum dmx_buffer_flags.
  *
  * This function callback prototype, provided by the client of the demux API,
  * is called from the demux code. The function is only called when filtering
@@ -245,7 +250,8 @@ typedef int (*dmx_ts_cb)(const u8 *buffer1,
 			 size_t buffer1_length,
 			 const u8 *buffer2,
 			 size_t buffer2_length,
-			 struct dmx_ts_feed *source);
+			 struct dmx_ts_feed *source,
+			 u32 *buffer_flags);
 
 /**
  * typedef dmx_section_cb - DVB demux TS filter callback function prototype
@@ -261,6 +267,10 @@ typedef int (*dmx_ts_cb)(const u8 *buffer1,
  *			including headers and CRC.
  * @source:		Indicates which section feed is the source of the
  *			callback.
+ * @buffer_flags:	Address where buffer flags are stored. Those are
+ * 			used to report discontinuity users via DVB
+ *			memory mapped API, as defined by
+ *			&enum dmx_buffer_flags.
  *
  * This function callback prototype, provided by the client of the demux API,
  * is called from the demux code. The function is only called when
@@ -286,7 +296,8 @@ typedef int (*dmx_section_cb)(const u8 *buffer1,
 			      size_t buffer1_len,
 			      const u8 *buffer2,
 			      size_t buffer2_len,
-			      struct dmx_section_filter *source);
+			      struct dmx_section_filter *source,
+			      u32 *buffer_flags);
 
 /*
  * DVB Front-End
diff --git a/include/media/dvb_demux.h b/include/media/dvb_demux.h
index b07092038f4b..3b6aeca7a49e 100644
--- a/include/media/dvb_demux.h
+++ b/include/media/dvb_demux.h
@@ -115,6 +115,8 @@ struct dvb_demux_filter {
  * @pid:	PID to be filtered.
  * @timeout:	feed timeout.
  * @filter:	pointer to &struct dvb_demux_filter.
+ * @buffer_flags: Buffer flags used to report discontinuity users via DVB
+ *		  memory mapped API, as defined by &enum dmx_buffer_flags.
  * @ts_type:	type of TS, as defined by &enum ts_filter_type.
  * @pes_type:	type of PES, as defined by &enum dmx_ts_pes.
  * @cc:		MPEG-TS packet continuity counter
@@ -145,6 +147,8 @@ struct dvb_demux_feed {
 	ktime_t timeout;
 	struct dvb_demux_filter *filter;
 
+	u32 buffer_flags;
+
 	enum ts_filter_type ts_type;
 	enum dmx_ts_pes pes_type;
 
diff --git a/include/media/dvb_vb2.h b/include/media/dvb_vb2.h
index af9aeccb0b41..c10c163963e3 100644
--- a/include/media/dvb_vb2.h
+++ b/include/media/dvb_vb2.h
@@ -85,6 +85,12 @@ struct dvb_buffer {
  * @nonblocking:
  *		If different than zero, device is operating on non-blocking
  *		mode.
+ * @flags:	buffer flags as defined by &enum dmx_buffer_flags.
+ *		Filled only at &DMX_DQBUF. &DMX_QBUF should zero this field.
+ * @count:	monotonic counter for filled buffers. Helps to identify
+ *		data stream loses. Filled only at &DMX_DQBUF. &DMX_QBUF should
+ *		zero this field.
+ *
  * @name:	name of the device type. Currently, it can either be
  *		"dvr" or "demux_filter".
  */
@@ -100,6 +106,10 @@ struct dvb_vb2_ctx {
 	int	buf_siz;
 	int	buf_cnt;
 	int	nonblocking;
+
+	enum dmx_buffer_flags flags;
+	u32	count;
+
 	char	name[DVB_VB2_NAME_MAX + 1];
 };
 
@@ -114,7 +124,7 @@ static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx)
 	return 0;
 };
 #define dvb_vb2_is_streaming(ctx) (0)
-#define dvb_vb2_fill_buffer(ctx, file, wait) (0)
+#define dvb_vb2_fill_buffer(ctx, file, wait, flags) (0)
 
 static inline unsigned int dvb_vb2_poll(struct dvb_vb2_ctx *ctx,
 					struct file *file,
@@ -153,9 +163,13 @@ int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx);
  * @ctx:	control struct for VB2 handler
  * @src:	place where the data is stored
  * @len:	number of bytes to be copied from @src
+ * @buffer_flags:
+ *		pointer to buffer flags as defined by &enum dmx_buffer_flags.
+ *		can be NULL.
  */
 int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
-			const unsigned char *src, int len);
+			const unsigned char *src, int len,
+			enum dmx_buffer_flags *buffer_flags);
 
 /**
  * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV
-- 
2.14.3