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

[Eric Biggers <ebiggers@kernel.org>]

On Mon, Jul 13, 2026 at 06:47:07AM +0200, Greg KH 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.
> 
> Why not just delete it now, and then bring it back when it is needed in
> the future?  Otherwise this will just trip up the static code checkers
> who will attempt to "fix" things in it.

That makes sense to me, but Qualcomm pushed back on deletion:
https://lore.kernel.org/linux-crypto/20260602-qcom-qce-broken-v1-1-a4ef756089e0@oss.qualcomm.com/

But I've still not seen any evidence that this driver is useful for
anything or has any users.  Even Qualcomm seems to be unwilling to make
such claims; they only claim that the IP is used (i.e., not in Linux)
and that new features are planned.

- Eric