JFFS2 doesn't mount read-only at boot in 2.6.22.1 anymore

[Eric BENARD]

Hi,

I'm testing Linux 2.6.22.1 on an AT91RM9200.
Before, with 2.6.21-rc5-gce20269d-dirty, I was able to pass "ro" option
on the boot command line and the rootfs was mounted readonly showing the
following message :
VFS: Mounted root (jffs2 filesystem) readonly.

Now, on 2.6.22.1, the "ro" option (same board, same rootfs), leads to
this message :
VFS: Mounted root (jffs2 filesystem).

The command line is (same in both case) :
root=/dev/mtdblock2 rootfstype=jffs2 console=ttyS0,115200
mtdparts=physmap-flash.0:256k(u-boot),1408k(kernel),-(rootfs) mem=32M ro

The config file for 2.6.22.1 is taken from 2.6.21-rc5 + make oldconfig
and default answer everywhere.

Do you have any idea of what may be wrong in my configuration ?
Is this an expected behaviour in 2.6.22.1 ?
Do you have any idea of where to dig to fix this problem ?

Thanks and best regards
Eric