build failure due to ROOT_DEV in mtd module (was Re: linux-2.6.22-rc5-g7c8545e build #298 failed ...)

[Satyam Sharma]

On 6/21/07, Christoph Hellwig <hch at infradead.org> wrote:
> On Thu, Jun 21, 2007 at 12:22:01PM +0530, Satyam Sharma wrote:
> > >> The build seems to fail because of:
> > >> ERROR: "ROOT_DEV" [drivers/mtd/maps/nettel.ko] undefined!
> > >>
> > >> After taking a quick look at the code, I can't immediately see why
> > >> this would be, since there is an include for linux/root_dev.h at the
> > >> top, there.
> > >>
> > >> There's only one occurrence of ROOT_DEV (line 425), and after a quick
> > >> look at the git history, it seems the include was originally missing,
> > >> but was put back in, in commit
> > >> 6cc449c7d0292cb9b993f0df84fd3225e3099492.
>
> Please just the reference to ROOT_DEV from this driver.  Just because
> someone builds this driver there should be no change in the default root
> device.

I agree, but this (drivers/mtd/maps/nettel.c) isn't the only modular driver
referencing ROOT_DEV. We also have drivers/mtd/maps/pmcmsp-ramroot.c
using ROOT_DEV (in fact the purpose of that driver seems to be precisely
to special-case the root fs and do something with it ...) but considering
that other driver's (tristate) Kconfig option depends on another symbol that
is non-existent in the mainline tree, there is no way someone can build
pmcmsp-ramroot and so we'll never actually  hit that problem even with an
allmodconfig build.

Anyway, I'll leave this up to David / linux-mtd to sort out. [ No other
modular user of ROOT_DEV in the tree other than the two mtd drivers
mentioned here. ]