On Mon, Mar 22, 2021 at 04:53:18PM +0100, Maxime Ripard wrote:

Indeed, I somehow missed that you were setting the DUN in
cqhci_crypto_prep_task_desc, and I'm guessing that's where my issue
lies: it doesn't look like there's any field to set the DUN in the
controller, which doesn't make much sense to me.

The documentation is pretty short, but it looks like it might be
inferred from the MMC commands arguments (the Access Mode bit in the MMC
controller, page 517). Would that make sense?

If your hardware has no way to specify a starting DUN (or starting IV) for each
request, then presumably it automatically chooses IVs based on the location of
the data on-disk.

This way of IV generation is problematic for several reasons, and it doesn't
match the UFS and eMMC standards.  So blk-crypto and fscrypt don't support this
type of hardware.

- Eric