A few weeks ago I had taken the time to write a small mod to the dvb
drivers that allows me to enable or disable zigzagging with a ioctl
call. I need it because I like to move my parabola to point to
different satellites, and the signal strength indication is
frustratingly useless as a help for correct alignment if tuning is
happily jumpimg up and down.
I added two IOCTL's, called FE_ZIGZAG and FE_DONT_ZIGZAG. The patch is
very simple, and works fine here. I have made sure that, if these
ioctls are not used, there is no change in behaviour.
I have now generated a patch file from plain linuxtv-dvb-1.0.0, that I
am including in this message. Is there some possibility to have this
applied to the main tree?
Thanks.
Carlo
--
* Se la Strada e la sua Virtu' non fossero state messe da parte,
* K * Carlo E. Prelz - [EMAIL PROTECTED] che bisogno ci sarebbe
* di parlare tanto di amore e di rettitudine? (Chuang-Tzu)
diff -urN linuxtv-dvb-1.0.0-orig/driver/dvb_frontend.c
linuxtv-dvb-1.0.0/driver/dvb_frontend.c
--- linuxtv-dvb-1.0.0-orig/driver/dvb_frontend.c 2003-08-01 17:27:21.000000000
+0200
+++ linuxtv-dvb-1.0.0/driver/dvb_frontend.c 2003-08-05 07:31:34.000000000 +0200
@@ -71,6 +71,7 @@
int lost_sync_count;
int exit;
fe_status_t status;
+ unsigned char dont_zigzag;
};
@@ -400,27 +401,30 @@
/**
* let's start a zigzag scan to compensate LNB drift...
*/
- if (fe->info->type == FE_QPSK)
- stepsize = fe->parameters.u.qpsk.symbol_rate / 16000;
- else if (fe->info->type == FE_QAM)
- stepsize = 0;
- else
- stepsize = fe->info->frequency_stepsize * 2;
+ if(!fe->dont_zigzag)
+ {
+ if (fe->info->type == FE_QPSK)
+ stepsize = fe->parameters.u.qpsk.symbol_rate / 16000;
+ else if (fe->info->type == FE_QAM)
+ stepsize = 0;
+ else
+ stepsize = fe->info->frequency_stepsize * 2;
+
+ if (j % 32 == 0) {
+ fe->lnb_drift = 0;
+ } else {
+ fe->lnb_drift = -fe->lnb_drift;
+ if (j % 2)
+ fe->lnb_drift += stepsize;
+ }
+
+ dvb_frontend_set_parameters (fe, &fe->parameters, 0);
+ dvb_frontend_internal_ioctl (&fe->frontend, FE_RESET, NULL);
- if (j % 32 == 0) {
- fe->lnb_drift = 0;
- } else {
- fe->lnb_drift = -fe->lnb_drift;
- if (j % 2)
- fe->lnb_drift += stepsize;
}
-
- dvb_frontend_set_parameters (fe, &fe->parameters, 0);
- dvb_frontend_internal_ioctl (&fe->frontend, FE_RESET, NULL);
}
-
static
int dvb_frontend_is_exiting (struct dvb_frontend_data *fe)
{
@@ -567,6 +571,7 @@
if (down_interruptible (&fe->sem))
return -EINTR;
+ fe->dont_zigzag = 0;
fe->exit = 0;
fe->thread_pid = 0;
mb();
@@ -624,6 +629,12 @@
case FE_GET_EVENT:
err = dvb_frontend_get_event (fe, parg, file->f_flags);
break;
+ case FE_ZIGZAG:
+ fe->dont_zigzag=0;
+ break;
+ case FE_DONT_ZIGZAG:
+ fe->dont_zigzag=1;
+ break;
case FE_GET_FRONTEND:
memcpy (parg, &fe->parameters,
sizeof (struct dvb_frontend_parameters));
diff -urN linuxtv-dvb-1.0.0-orig/include/linux/dvb/frontend.h
linuxtv-dvb-1.0.0/include/linux/dvb/frontend.h
--- linuxtv-dvb-1.0.0-orig/include/linux/dvb/frontend.h 2003-05-08 15:50:10.000000000
+0200
+++ linuxtv-dvb-1.0.0/include/linux/dvb/frontend.h 2003-08-04 20:22:43.000000000
+0200
@@ -258,6 +258,8 @@
#define FE_GET_FRONTEND _IOR('o', 77, struct dvb_frontend_parameters)
#define FE_GET_EVENT _IOR('o', 78, struct dvb_frontend_event)
+#define FE_ZIGZAG _IO('o', 79)
+#define FE_DONT_ZIGZAG _IO('o', 80)
#endif /*_DVBFRONTEND_H_*/
