V4L/DVB (10854): cx18: Correct comments about vertical and horizontal blanking timings

[pandora-kernel.git] / drivers / media / video / cx18 / cx18-av-core.c

diff --git a/drivers/media/video/cx18/cx18-av-core.c b/drivers/media/video/cx18/cx18-av-core.c
index aeeb3cf..21f4be8 100644 (file)
--- a/drivers/media/video/cx18/cx18-av-core.c
+++ b/drivers/media/video/cx18/cx18-av-core.c
@@ -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;