Handling multiple NAND chips -- take 2

J.D. Bakker bakker at thorgal.et.tudelft.nl
Wed Feb 25 14:19:54 EST 2004

At 5:59 PM +0000 25/2/04, David Woodhouse wrote:
>Join us on IRC and tglx can heckle you too :)

Time to install an IRC client, I suppose.


>  > * All detected devices are concatenated and represented as one large
>>  linear array of pages
>Look at the DiskOnChip Millennium Plus address-mangling code and
>comments above DoC_GetDataOffset().
>If we could support that it would perhaps be useful.

I'll have a look at it, thanks.

>  > * All devices are soldered to a motherboard. We are not interested in
>>  taking devices out of the array.
>Not sure. Look at how the new DiskOnChip driver has to screw around
>before the chip probing, so it can pretend this is true. T'would be nice
>to deal with a sparse array, at least.

Maybe. I don't have much of a problem of returning -EIO (or another 
more applicable error code) when higher layers access a non-present 
device. Then again, I don't see a useful response in such a scenario. 
What is a file system to do when part of the underlying (block) 
device is imply Not There ?

I'd very much like to keep this simplification. It makes the code 
much simpler: you can just rely on the fact that the array consists 
of all devices that were found during a probe. No config options 
needed, no 'raid blocks' on the NANDs.

>And if you mean hotplug -- think SmartMedia.

I'd rather not, thanks. Seriously though, I don't see many useful 
applications for a hot-swappable linear array.


It was then I realized how dire my medical situation was.  Here I was,
a network admin, unable to leave, and here was someone with a broken
network.  And they didn't ask me to fix it.  They didn't even try to
casually pry a hint out of me.  -- Ryan Tucker , in the Monastery

More information about the linux-mtd mailing list