V4L/DVB (8774): cx18: Have CX23418 release buffers at end of capture.

cx18: Have CX23418 release buffers at end of capture.  The CX23418 reuses task
handles so we need to have it release the buffers associated with a task handle
at the end of a capture.  If we don't, buffer ids used for one type of stream
in the driver (MPEG, TS, PCM), could be used for another type of stream by the
CX23418, if a previously used handle is assigned to a different type of stream.
The driver would drop valid buffers when this happened.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-mailbox.c

@@ -82,6 +82,7 @@ static const struct cx18_api_info api_info[] = {
 	API_ENTRY(CPU, CX18_CPU_DE_SET_MDL_ACK,			0),
 	API_ENTRY(CPU, CX18_CPU_DE_SET_MDL,			API_FAST),
 	API_ENTRY(CPU, CX18_APU_RESETAI,			API_FAST),
+	API_ENTRY(CPU, CX18_CPU_DE_RELEASE_MDL,			0),
 	API_ENTRY(0, 0,						0),
 };
 

drivers/media/video/cx18/cx18-streams.c

@@ -488,7 +488,14 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
 	/* begin_capture */
 	if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
 		CX18_DEBUG_WARN("Error starting capture!\n");
+		/* Ensure we're really not capturing before releasing MDLs */
+		if (s->type == CX18_ENC_STREAM_TYPE_MPG)
+			cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1);
+		else
+			cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);
+		cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
 		cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
+		/* FIXME - clean-up DSP0_INT mask, i_flags, s_flags, etc. */
 		return -EINVAL;
 	}
 
@@ -540,6 +547,9 @@ int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
 		CX18_INFO("ignoring gop_end: not (yet?) supported by the firmware\n");
 	}
 
+	/* Tell the CX23418 it can't use our buffers anymore */
+	cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
+
 	if (s->type != CX18_ENC_STREAM_TYPE_TS)
 		atomic_dec(&cx->ana_capturing);
 	atomic_dec(&cx->tot_capturing);

drivers/media/video/cx18/cx23418.h

@@ -351,7 +351,7 @@
    Descriptor Lists to the driver
    IN[0] - Task handle. Handle of the task to start
    ReturnCode - One of the ERR_DE_... */
-/* #define CX18_CPU_DE_ReleaseMDL               (CPU_CMD_MASK_DE | 0x0006) */
+#define CX18_CPU_DE_RELEASE_MDL               	(CPU_CMD_MASK_DE | 0x0006)
 
 /* Description: This command signals the cpu that the dat buffer has been
    consumed and ready for re-use.