[linux-dvb] Re: TT DVB-T - Further problems

[Juergen Peitz <peitz@snafu.de>]

Sunday, 20. April 2003 16:52 Ed Wildgoose wrote:

> b) after changing channel more than a dozen or so times the driver
> appears to lock up, picture disappears from both TV output and also
> /dev/dvb devices.... No errors in the log, everything still "appears" to
> work fine, just no picture...

Can everybody who has tuning problems with the TT DVB-T card please try the 
attached patch and report if it gives any improvement. This code is from 
Holgers sp8872 driver and forces the card to use the given frontend 
parameters.
I also would like to know if this tuning problems also appear with the windows 
driver. My card doesn't has this problem so I can't test it myself.

Juergen 


--------------------------------------------------------------------------------------------------------

--- DVB_CVS/DVB/driver/frontends/alps_tdlb7.c	Mon Mar 17 11:47:34 2003
+++ DVB_CVS_NEW/DVB/driver/frontends/alps_tdlb7.c	Mon Apr 21 01:01:33 2003
@@ -287,6 +287,78 @@
 
 
 static
+int configure_reg0xc05 (struct dvb_frontend_parameters *p, u16 *reg0xc05)
+{
+	int known_parameters = 1;
+	
+	*reg0xc05 = 0x000;
+	switch (p->u.ofdm.constellation) {
+	case QPSK:
+		break;
+	case QAM_16:
+		*reg0xc05 |= (1 << 10);
+		break;
+	case QAM_64:
+		*reg0xc05 |= (2 << 10);
+		break;
+	case QAM_AUTO:
+		known_parameters = 0;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	switch (p->u.ofdm.hierarchy_information) {
+	case HIERARCHY_NONE:
+		break;
+	case HIERARCHY_1:
+		*reg0xc05 |= (1 << 7);
+		break;
+	case HIERARCHY_2:
+		*reg0xc05 |= (2 << 7);
+		break;
+	case HIERARCHY_4:
+		*reg0xc05 |= (3 << 7);
+		break;
+	case HIERARCHY_AUTO:
+		known_parameters = 0;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	switch (p->u.ofdm.code_rate_HP) {
+	case FEC_1_2:
+		break;
+	case FEC_2_3:
+		*reg0xc05 |= (1 << 3);
+		break;
+	case FEC_3_4:
+		*reg0xc05 |= (2 << 3);
+		break;
+	case FEC_5_6:
+		*reg0xc05 |= (3 << 3);
+		break;
+	case FEC_7_8:
+		*reg0xc05 |= (4 << 3);
+		break;
+	case FEC_AUTO:
+		known_parameters = 0;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	if (known_parameters){ 
+	    *reg0xc05 |= (2 << 1);	/* use specified parameters */
+	} else {
+	    *reg0xc05 |= (1 << 1);	/* enable autoprobing */
+	}
+	return 0;
+}
+
+
+static
 int tdlb7_ioctl (struct dvb_frontend *fe, unsigned int cmd, void *arg)
 {
 	struct dvb_i2c_bus *i2c = fe->i2c;
@@ -352,13 +424,21 @@
 
         case FE_SET_FRONTEND:
         {
+		u16 reg0xc05;
+		int err;	
 		struct dvb_frontend_parameters *p = arg;
 
+		if ((err = configure_reg0xc05(p, &reg0xc05)))
+		return err;
+
 		// system controller stop 
 		sp8870_writereg(i2c,0x0F00,0x0000);
 
 		sp5659_set_tv_freq (i2c, p->frequency);
 
+		/* read status reg in order to clear pending irqs */
+		sp8870_readreg(i2c, 0x200);
+		
 		// sample rate correction bit [23..17]
 		sp8870_writereg(i2c,0x0319,0x000A);
 		
@@ -384,6 +464,8 @@
 			sp8870_writereg(i2c,0x0338,0x0000);
 		else
 			sp8870_writereg(i2c,0x0338,0x0001);
+
+		sp8870_writereg(i2c, 0xc05, reg0xc05);
 
 		// instruction RAM register loword
 		sp8870_writereg(i2c,0x0F09,0x0000);



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