[PATCH] powerpc/config: Disable the 4KiB erase granularity of SPI flash

[David Laight]

From: Zhiqiang Hou
> Sent: 07 April 2016 04:17
...
> > Is there a reason specific to 85xx to have a different default than every other
> > platform except lpc18xx?  The description of MTD_SPI_NOR_USE_4K_SECTORS
> > acknowledges that erase speed is a tradeoff.  Why is that concern more
> > compelling on 85xx than elsewhere?
> >
> 
> I don't want to specify 85xx, but configs of fsl. I'm still confusing  about so many
> configs. Will add other platforms if necessary.
> 
> For this patch, it takes about 13 mins to erase 64MiB by subsector erase command
> (4KiB per time), but takes 2 mins by sector erase command(64KiB per time). It is
> conspicuous decrease. Why it uses the 4KiB granularity by default, what's the
> benefit?

Should it be doing 64K erases followed by 0 to 15 4K erases for any final fragment?

	David