goofy mtd m25p80 patches in GIT ...

[Chen Gong-B11801]

> 
> Second:
> 
>  
> http://git.kernel.org/?p=linux/kernel/git/dwmw2/mtd-2.6.git;a=
> commitdiff;h=75d0ee2202b5740e94e913d8a52f91c6557c4c81
> 
> That's just plain wrong ... the original code is correct, but the
> patch changed it to be incorrect.  (DMA from the stack is never
> legal.)
> 
> Just revert this one entirely.
> 
> 
I know spi_write_then_read is different from spi_write, but here n_rx & rxbuf are
both NULL, which means no real read operation are executed. Would you please
give me more explanation for potential hazard ?