[PATCH 1/5] powerpc: generic time suspend/resume code

[Guennadi Liakhovetski]

On Wed, 21 Mar 2007, David Brownell wrote:

> (*) Most of the I2C based RTCs rely on kernel command line parameters,
>     because of the vagaries of I2C.  "New style" I2C drivers will replace
>     command line declarations ("rv5c386 RTC on bus 0 at address 0x32")
>     with ones in the board specific init logic.

[OT] I know very well what you mean! After my recent patch i2c-pxa driver 
on PXA27x CPUs supports both i2c buses. Now, there are chips, like pcf8574 
that specify 16 (!) addresses in their normal list. Which means, to use it 
on a pxa27x with one such chip on 1 address and to avoid scanning them all 
and flooding your log with terrifying error messages (smth like "retries 
exhausted", I think), you have to specify an "ignore" list on the kernel 
command line / modprobe parameter with a list of (16 - 1)*2 + 16*2 = 62 
comma separated values (e.g., if it's on 0,0x20: 
ignore=0,0x21,...1,0x20,1,0x21,...)!... Which even exceeds max length of 
the ignore array. So, I had to double its length. Of course, changes like 
that I don't submit to the mainline:-)))

Looking forward to your reworked i2c.

Thanks
Guennadi
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Guennadi Liakhovetski