Re: [PATCH v12 00/12] crypto/dmaengine: qce: introduce BAM locking and use DMA for register I/O

From: Stephan Gerhold

Date: Wed Mar 11 2026 - 04:09:38 EST


On Wed, Mar 11, 2026 at 09:03:37AM +0100, Bartosz Golaszewski wrote:
> On Tue, Mar 10, 2026 at 4:44 PM Bartosz Golaszewski
> <bartosz.golaszewski@xxxxxxxxxxxxxxxx> wrote:
> >
> > This iteration is built on top of the v11 RFC with remaining issues
> > fixed and the mechanism for communicating the scratchpad address from
> > clients to the BAM driver changed from slave config to descriptor
> > metadata.
> >
> > However: during stress-testing I noticed that sometimes a transaction
> > would end with an error. The engine was indicating that a write/read to
> > the config registers was performed while the engine was busy (bit 17 of
> > the STATUS register was set). It turns out that we must not just
> > unconditionally append the UNLOCK descriptor to the "issued" queue, we
> > must wait for the transaction to end before we queue it so this version
> > takes this into account and queues the UNLOCK descriptor from the
> > workqueue.
> >
> > With this all stress tests and benchmarks from cryptsetup work fine.
> >
>
> Mani, Stephan: sorry, I forgot to update the cover letter to Cc you.
> Doing it now here.
>
> Stephan: I tried to use READ command but it would crash on sm8650, so
> I went with WRITE. :(
>

No worries, thanks for testing this!

Stephan