Re: [PATCH] accel: ethosu: Don't read the U65 rounding mode as a storage mode

[Rob Herring <robh@kernel.org>]

On Mon, Aug 24, 2026 at 05:26:11PM +0200, Tomeu Vizoso wrote:
> Bits 15:14 of NPU_SET_{IFM,OFM}_PRECISION select the activation storage
> mode on U85 only. On U65 the same field holds the rounding mode, and the
> command stream parser has read it as a storage mode since the driver was
> added.
> 
> That went unnoticed while unknown values fell through the switch, but
> now that they are rejected, every U65 command stream that asks for
> natural rounding (2) fails CMDSTREAM_BO_CREATE with -EINVAL. Mesa emits
> it for average pooling, concatenation, split, unpack, strided slice, LUT
> and argmax, which is 72 failures of the Teflon test suite on an i.MX93.
> Truncating rounding (1) is misread as well: it picks the two-tile
> address path and computes a bogus feature map size from tile bases the
> command stream never set.
> 
> Read the field as a storage mode only on the hardware where it is one.
> 
> Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
> Fixes: 6b7e0066294d ("accel: ethosu: Handle U85 internal chaining buffer")
> Assisted-by: Claude:claude-opus-5
> Signed-off-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>
> ---
>  drivers/accel/ethosu/ethosu_gem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied.

I guess I failed to update the i.MX93 kernel with my fix. Sorry about 
that.

Rob