[linux-dvb] [PATCH] AverMedia AverTV DVB-T 761

Jyrki Niskala jyrki.n at telia.com
Sat Sep 10 21:50:01 CEST 2005


Johannes Stezenbach wrote:

>On Sat, Sep 03, 2005 Jyrki Niskala wrote:
>  
>
>>This patch gives better performance when using high frequencies (over 
>>470 MHz). I got those new
>>charge pump values by i2c-snooping windows drivers.
>>    
>>
>...
>  
>
>>--- dvb-kernel/linux/drivers/media/dvb/bt8xx/org-dvb-bt8xx.c    
>>2005-09-03 19:21:55.000000000 +0200
>>+++ dvb-kernel/linux/drivers/media/dvb/bt8xx/dvb-bt8xx.c        
>>2005-09-03 19:23:11.000000000 +0200
>>@@ -264,10 +264,10 @@
>>               cpump = 1;
>>       else if (params->frequency < 470000000)
>>               cpump = 2;
>>-       else if (params->frequency < 750000000)
>>-               cpump = 2;
>>-       else
>>-               cpump = 3;
>>+        else if (params->frequency < 750000000)
>>+               cpump = 0x40;
>>+        else
>>+               cpump = 0xc0;
>>
>>       if (params->frequency < 175000000)
>>               band_select = 0x0e;
>>    
>>
>
>Hm, that's not the real fix, there seems to be another bug.
>Can you try the following patch:
>
>
>--- linux/drivers/media/dvb/bt8xx/dvb-bt8xx.c	10 Sep 2005 07:26:02 -0000	1.49
>+++ linux/drivers/media/dvb/bt8xx/dvb-bt8xx.c	10 Sep 2005 16:52:52 -0000
>@@ -280,7 +280,7 @@ static int microtune_mt7202dtf_pll_set(s
> 	data[0] = (div >> 8) & 0x7f;
> 	data[1] = div & 0xff;
> 	data[2] = ((div >> 10) & 0x60) | cfg;
>-	data[3] = cpump | band_select;
>+	data[3] = (cpump << 6) | band_select;
> 
> 	i2c_transfer(card->i2c_adapter, &msg, 1);
> 	return (div * 166666 - 36000000);
>
>Additionally the Windows driver seems to use slightly
>different charge pump settings (1 vs. 2 in the 470...750MHz range),
>can you test which one actually works better?
>
>Thanks,
>Johannes
>
>  
>
I think your patch affects all frequencies, i have only 4 mux from 538 
MHz to 778 MHz to test on.
But I will give it a go asap.

By the way, this is my i2c log, it may be a outdated windows driver 
since the log is from april 2004 ;-)

Milksop GPL Reflasher - 0.20 - (c)2002 andy at warmcat.com
...
### zap to TV3 @ 706 MHz:
405uS: 70 W 02 06 00 01 . . .
690uS: 60 W 11 64 88 43 d . C
627uS: 70 W 0C 18 .
356uS: 70 r 00 0D .
433uS: 70 W 02 06 00 00 . . .
### zap to TV4 @ 746 MHz:
432uS: 70 W 02 06 00 01 . . .
636uS: 60 W 12 54 88 43 T . C
612uS: 70 W 0C 18 .
374uS: 70 r 00 0D .
463uS: 70 W 02 06 00 00 . . .
### zap to SVT1 @ 778 MHz:
400uS: 70 W 02 06 00 01 . . .
606uS: 60 W 13 14 88 C3 . . .
605uS: 70 W 0C 18 .
378uS: 70 r 00 0D .
397uS: 70 W 02 06 00 00 . . .
#### zap to ZTV @ 538 MHz:
403uS: 70 W 02 06 00 01 . . .
646uS: 60 W 0D 74 88 43 t . C
629uS: 70 W 0C 18 .
358uS: 70 r 00 0D .
422uS: 70 W 02 06 00 00 . . .
...

/ Jyrki





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