[linux-dvb] 2.6.20 -> saa i2c messages

Udo van den Heuvel udovdh at xs4all.nl
Thu Feb 15 16:56:47 CET 2007


Hello,

Pavel Paprok wrote:
> i dont know exactly but i meet maybe similar problems
> with i2c and saa7146 a year ago..
>  
> hi,
> maybe something is wrong with i2c bus so you can primarily try
> to increase variable SAA7146_I2C_RETRIES to bigger value (~20)
> to eliminate these problems, it works good for me.
> next you can also try to change SAA7146_I2C_BUS_BIT_RATE_value
> if it is object of your hardware..
> 
> you can find my full story on
> http://www.linuxtv.org/pipermail/linux-dvb/2006-March/008829.html
> first and last part of this message maybe related to your problem...

Thanks for the very interesting technical info!
Unfortunately it did not (yet) solve my problems.

On 2.6.19.2 everything works fine. I have a VIA Epia EN12000 with a duo
of Terratec Cinergy 1200 DVB-T (in use) and a Terratec Cinergy 1200
DVB-S (to be used).
When I boot into 2.6.20 I get a load of the previously posted i2c messages.

I have on this system:

  Installed I2C busses:
    i2c-2       i2c             TerraTec Cinergy 1200 DVB-S
    i2c-1       i2c             Terratec Cinergy 1200 DVB-T
    i2c-0       smbus           SMBus Via Pro adapter at 0500

i2cdump -y  2 0x68 on 2.6.19.2 gives me a dump without errors.
Same for i2cdump -y  1 0x08. (DVB-T card)

In budget-core.c I changed to SAA7146_I2C_BUS_BIT_RATE_480 in
saa7146_i2c_adapter_prepare.
In drivers/media/common/saa7146_i2c.c I also changed
timeout = HZ/100 + 1; /* 10ms */ to
timeout = 20*HZ/100 + 1; /* 200ms? */.

Still I get loads of the messages. Even more than before due to the
increased retries in include/media/saa7146.h. (why are there three
saa7146.h's on my system!?: drivers/media/video/saa7146.h,
include/config/video/saa7146.h and include/media/saa7146.h)

Any idea what to change/try next?
SAA7146_I2C_DELAY?

How can I test the i2c to the cards thoroughly without rebooting?
(iscdump?)


Kind regards,
Udo



BTW: Is the LNBP21 CURRENT LIMIT info also in effect for the Terratec cards?





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