media: dvb: add continuity error indicators for memory mapped buffers

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>

1 files changed, 35 insertions, 0 deletions

diff --git a/include/uapi/linux/dvb/dmx.h b/include/uapi/linux/dvb/dmx.h
index 5f3c5a918f00..b4112f0b6dd3 100644
--- a/include/uapi/linux/dvb/dmx.h
+++ b/include/uapi/linux/dvb/dmx.h
@@ -212,6 +212,32 @@ struct dmx_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
  *
  * @index:	id number of the buffer
@@ -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;
 };
 
 /**