Commit af7c58b1 authored by Andy Walls's avatar Andy Walls Committed by Mauro Carvalho Chehab
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V4L/DVB (10854): cx18: Correct comments about vertical and horizontal blanking timings 



This change only affects comments.

Signed-off-by: default avatarAndy Walls <awalls@radix.net>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 583803d1

drivers/media/video/cx18/cx18-av-core.c

+16 −10
Original line number Diff line number Diff line
@@ -292,23 +292,29 @@ void cx18_av_std_setup(struct cx18 *cx) 
		 *

		 * vsync:     always 6 half-lines of vsync pulses

		 * vactive:   half lines of active video

		 * vblank656: half lines, after line 3, of blanked video

		 * vblank:    half lines, after line 9, of blanked video

		 * vblank656: half lines, after line 3/mid-266, of blanked video

		 * vblank:    half lines, after line 9/272, of blanked video

		 *

		 * As far as I can tell:

		 * vblank656 starts counting from the falling edge of the first

		 * 	vsync pulse (start of line 4)

		 * 	vsync pulse (start of line 4 or mid-266)

		 * vblank starts counting from the after the 6 vsync pulses and

		 * 	6 equalization pulses (start of line 10)

		 * 	6 or 5 equalization pulses (start of line 10 or 272)

		 *

		 * For 525 line systems the driver will extract VBI information

		 * from lines 10 through 21.  To avoid the EAV RP code from

		 * toggling at the start of hblank at line 22, where sliced VBI

		 * data from line 21 is stuffed, also treat line 22 as blanked.

		 * from lines 10-21 and lines 273-284.

		 */

		vblank656 = 38; /* lines  4 through  22 */

		vblank = 26;	/* lines 10 through  22 */

		vactive = 481;  /* lines 23 through 262.5 */

		vblank656 = 38; /* lines  4 -  22  &  266 - 284 */

		vblank = 26;	/* lines 10 -  22  &  272 - 284 */

		vactive = 481;  /* lines 23 - 263  &  285 - 525 */



		/*

		 * For a 13.5 Mpps clock and 15,734.26 Hz line rate, a line is

		 * is 858 pixels = 720 active + 138 blanking.  The Hsync leading

		 * edge should happen 1.2 us * 13.5 Mpps ~= 16 pixels after the

		 * end of active video, leaving 122 pixels of hblank to ignore

		 * before active video starts.

		 */

		hactive = 720;

		hblank = 122;

		luma_lpf = 1;

drivers/media/video/cx18/cx18-av-core.h

+12 −7
Original line number Diff line number Diff line
@@ -89,16 +89,21 @@ struct cx18_av_state { 


	/*

	 * The VBI slicer starts operating and counting lines, begining at

	 * slicer line count of 1, at D lines after the deassertion of VRESET

	 * This staring field line, S, is 6 or 10 for 625 or 525 line systems.

	 * Sliced ancillary data captured on VBI slicer line M is sent at the

	 * beginning of the next VBI slicer line, VBI slicer line count N = M+1.

	 * Thus when the VBI slicer reports a VBI slicer line number with

	 * ancillary data, the IDID0 byte indicates VBI slicer line N.

	 * The actual field line that the captured data comes from is

	 * slicer line count of 1, at D lines after the deassertion of VRESET.

	 * This staring field line, S, is 6 (& 319) or 10 (& 273) for 625 or 525

	 * line systems respectively.  Sliced ancillary data captured on VBI

	 * slicer line M is inserted after the VBI slicer is done with line M,

	 * when VBI slicer line count is N = M+1.  Thus when the VBI slicer

	 * reports a VBI slicer line number with ancillary data, the IDID0 byte

	 * indicates VBI slicer line N.  The actual field line that the captured

	 * data comes from is

	 *

	 * L = M+(S+D-1) = N-1+(S+D-1) = N + (S+D-2).

	 *

	 * L is the line in the field, not frame, from which the VBI data came.

	 * N is the line reported by the slicer in the ancillary data.

	 * D is the slicer_line_delay value programmed into register 0x47f.

	 * S is 6 for 625 line systems or 10 for 525 line systems

	 * (S+D-2) is the slicer_line_offset used to convert slicer reported

	 * line counts to actual field lines.

	 */

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

+2 −3
Original line number Diff line number Diff line
@@ -413,9 +413,8 @@ static void cx18_vbi_setup(struct cx18_stream *s) 
		 * 0x90 (Task                         HorizontalBlank)

		 * 0xd0 (Task EvenField               HorizontalBlank)

		 *

		 * We have set the digitzer to consider the first active line

		 * as part of VerticalBlank as well so we don't have to look for

		 * these problem codes nor lose the last line of sliced data.

		 * We have set the digitzer such that we don't have to worry

		 * about these problem codes.

		 */

		data[4] = 0xB0F0B0F0;

		/*