Re: [PATCH v2] drivers/crypto: Mark QCE as BROKEN

[Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>]

On Fri, Jul 17, 2026 at 06:18:48PM +1000, Herbert Xu wrote:
> On Sun, Jul 12, 2026 at 05:31:31PM -0400, Demi Marie Obenour via B4 Relay wrote:
> > From: Demi Marie Obenour <demiobenour@gmail.com>
> >
> > This driver is harmful:
> >
> > - It is much slower than the CPU [1] [2].
> > - It Has a history of bugs [2] [3].
> > - It does not have exclusive access to the hardware [4], causing races
> >   with the secure world.
> > - It register its implementations with too low a cra_priority for them
> >   to be actually used [5].
> >
> > Therefore, disable it to ensure that nobody builds it into kernels they
> > intend to ship.
> >
> > In the future, the driver will be used for processing restricted media
> > content.  However, the kernel does not currently support this.  Since
> > the driver will have future uses, allow building it if COMPILE_TEST is
> > enabled.
> >
> > [1]: https://lore.kernel.org/r/20250704070322.20692-1-ebiggers@kernel.org/
> > [2]: https://lore.kernel.org/r/20250615031807.GA81869@sol/
> > [3]: https://lore.kernel.org/r/20260706-qce-fix-self-tests-v5-0-86f461ff1829@oss.qualcomm.com/
> > [4]: https://lore.kernel.org/r/20260629-qcom-qce-cmd-descr-v20-0-56f67da84c05@oss.qualcomm.com/
> > [5]: https://lore.kernel.org/r/20260524204537.GB110177@quark/
> >
> > Fixes: ec8f5d8f6f76 ("crypto: qce - Qualcomm crypto engine driver")
> > Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
> > ---
> > Changes in v2:
> > - Add Fixes: ec8f5d8f6f76 ("crypto: qce - Qualcomm crypto engine driver")
> > - Add Cc: stable@vger.kernel.org
> > - Link to v1: https://lore.kernel.org/r/20260712-qce-broken-v1-1-85e2bff17871@gmail.com
> > ---
> >  arch/arm/configs/multi_v7_defconfig | 1 -
> >  arch/arm64/configs/defconfig        | 1 -
> >  drivers/crypto/Kconfig              | 6 +++++-
> >  3 files changed, 5 insertions(+), 3 deletions(-)
>
> Patch applied.  Thanks.

Hi Herbert,

I'd like to ask you to back this patch out. Admittedly I should have NAKed this
under the v1 thread but I thought the discussion we had under the Shikra series
and the subsequent patch making myself the maintainer of this driver (note: Demi
did not Cc me on this nor the Qcom mailing list at linux-arm-msm) as well as the
pending series[1] fixing the QCE issues was enough to imply we should not mark
it as broken. Please consider applying [1] if the fixes in v6 are correct.

Bartosz

[1] https://lore.kernel.org/all/20260717-qce-fix-self-tests-v6-0-455775fe5f6c@oss.qualcomm.com/