mtd concatenate support for pxa2xx-flash mapping driver

[Jeff Sutherland]

On Friday 05 September 2008, apparently Vernon Sauder wrote:
> Jeff Sutherland wrote:
> > I'm working currently in 2.6.25.  Is anyone working on mtd concatenation
> > support for this particular driver?  $customer selected 64Mbyte NOR flash
> > chip for root filesystem, but in reality it is two 32Mb die in one
> > package, and I need one mtd partition > 32mb after taking care of
> > bootloader, environment, and kernel.
>
> Is this the P30 strataflash 48F4400 variety? I created a custom patch
> for that but converted to using the phymap-flash support from 2.6.25.1
> and backported it to 2.6.24.4. I use the command line parsing.

I got this sorted out today.  It turns out the physmap-flash driver will fail 
silently if you specify a command line partition that spans twom chips.  In 
other words, I had specified in the kernel config the total size of installed 
flash, but had left unchecked config_mtd_concat.  On startup physmap-flash 
would correctly identify both chips inside the 48F4400 part, and even let me 
make a partition (passed in from the kernel command line) that spanned the 
boundary between chips.  But jffs2 had a cow with the smaller erase blocks at 
the 32m boundary.  Simply turning on CONFIG_MTD_CONCAT solved all the 
problems, sigh...

Regards,
-Jeff