[linux-dvb] dvb/cvs: _SFBUF must be called? doh!

[Guido Draheim <guidod-2003-@gmx.de>]

The _SWIN (set window/format) ioctl call will fail
without a prior call to _SFBUF (set frame buffer).

Reason: move_to() rejects the initial null set into data->buffer
during av7110_*_attach. To require _SFBUF seems wrong to me, but
I did not find a good V4L(1) api description anyway (according
to V4L2 it is really wrong). No _SWIN ioctl can ever succeed ATM.

Just wondering about that while debugging into problems of
my `zapping` v4l viewer with dvb modules for 2.4, cvs version.
Here there is even a more severe problem, as it does also
_read_ the current window size from the driver but the
current dvb modules do not implement this functionality.

The following patch can fix parts of bad behavior
with implementing VIDIOCGWIN / SAA7146_V4L_GWIN.
That one just copies back the data->window area
to the user space. We also change the behavior
of SAA7146_V4L_SWIN slightly, so that the two
data->window.height and .width members are setup
after some successful set_window() call (where
they can be asserted) which is before that move_to()
call that will still fail (for the _SFBUF not yet
performed).

Only with this patch I can run the v4l viewer with
latest cvs dvb drivers (on a siemens dvb-s 1.3).

cheers,
-- guido                                  http://google.de/search?q=guidod
GCS/E/S/P C++/++++$ ULHS L++w- N++@ d(+-) s+a- r+@>+++ y++ 5++X- (geekcode)

? dvb-v4l_gwin-03.patch
Index: driver/av7110/av7110.c
===================================================================
RCS file: /cvs/linuxtv/DVB/driver/av7110/av7110.c,v
retrieving revision 1.52
diff -u -r1.52 av7110.c
--- driver/av7110/av7110.c	2 Jun 2003 18:02:19 -0000	1.52
+++ driver/av7110/av7110.c	11 Jun 2003 01:33:04 -0000
@@ -3091,7 +3091,10 @@
 
         case VIDIOCGWIN:
         {
+                struct video_window *w = arg;
                 dprintk(KERN_ERR "dvb: VIDIOCGWIN called\n");
+
+                saacomm(SAA7146_V4L_GWIN, w);
                 return 0;
         }
 
Index: driver/av7110/saa7146_v4l.c
===================================================================
RCS file: /cvs/linuxtv/DVB/driver/av7110/saa7146_v4l.c,v
retrieving revision 1.3
diff -u -r1.3 saa7146_v4l.c
--- driver/av7110/saa7146_v4l.c	7 Nov 2002 19:43:32 -0000	1.3
+++ driver/av7110/saa7146_v4l.c	11 Jun 2003 01:33:04 -0000
@@ -153,7 +153,11 @@
 			video_setmode(saa, 0);
 			saa7146_write(saa->mem, MC1, (MASK_21));
 
-			set_window(saa, vw->width, vw->height,0,0,0);
+			if (! set_window(saa, vw->width, vw->height,0,0,0))
+			{
+			    data->window.height = vw->height;
+			    data->window.width  = vw->width;
+			}
 			//saa->port, saa->sync);
 			if (move_to(saa, vw->x, vw->y, vw->height, data->buffer.width,
 				    data->buffer.depth, data->buffer.bytesperline,
@@ -227,6 +231,12 @@
 			video_setmode(saa, 1);
 			break;
 		}
+		case SAA7146_V4L_GWIN:
+		{
+			memcpy(arg, &data->window, sizeof(struct video_window));
+			break;
+		}
+
 
 		case SAA7146_V4L_CCAPTURE:
 		{
Index: driver/av7110/saa7146_v4l.h
===================================================================
RCS file: /cvs/linuxtv/DVB/driver/av7110/saa7146_v4l.h,v
retrieving revision 1.2
diff -u -r1.2 saa7146_v4l.h
--- driver/av7110/saa7146_v4l.h	10 Oct 2002 19:22:29 -0000	1.2
+++ driver/av7110/saa7146_v4l.h	11 Jun 2003 01:33:04 -0000
@@ -25,6 +25,8 @@
 
 #define	SAA7146_V4L_TSCAPTURE  		_IOW('d', (SAA7146_V4L_BASE+11), int)
 
+#define	SAA7146_V4L_GWIN	    	_IOW('d', (SAA7146_V4L_BASE+12), struct video_window)
+
 extern int saa7146_v4l_init (void);
 extern void saa7146_v4l_exit (void);