[U-Boot] convention for SPI dummy data?

[Wolfgang Wegner]

On Fri, Apr 23, 2010 at 11:34:53AM -0400, Mike Frysinger wrote:
[...]
> > the problem exists in the (coldfire) SPI driver, not in the MMC/SD code.
> 
> sorry, i thought you were proposing to fix it in the SPI/MMC driver

no, as far as I can see it is always set to 0xFF there if set explicitly,
i.e. except for the read-only transfers.

> what i've seen so far is that the idle val doesnt matter to most spi devices.  
> so on the Blackfin side, we've been defaulting to 0xff so that things do work 
> "out of the box" for everyone (at least so far).

Sounds good - however I had just sent a patch implementing CONFIG_SPI_IDLE_VAL.

(I am quite hesitating to simply change such a basic default value because
I fear there might be other devices around relying on current behaviour.
On the other hand, my implementation adds 7 lines of preprocessor stuff,
which also does not look really good.)

Regards,
Wolfgang