On 21-10-21, 15:17, Viresh Kumar wrote:

The virtio specification received a new mandatory feature
(VIRTIO_I2C_F_ZERO_LENGTH_REQUEST) for zero length requests. Fail if the
feature isn't offered by the device.

For each read-request, set the VIRTIO_I2C_FLAGS_M_RD flag, as required
by the VIRTIO_I2C_F_ZERO_LENGTH_REQUEST feature.

This allows us to support zero length requests, like SMBUS Quick, where
the buffer need not be sent anymore.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
Hi Wolfram,

Please do not apply this until the spec changes [1] are merged, sending it early
to get review done. I will ping you later once the spec is merged.

[1] https://lists.oasis-open.org/archives/virtio-dev/202110/msg00109.html

Michael,

Can this be merged as well based on the current voting at the ballot ?

https://www.oasis-open.org/committees/ballot.php?id=3659

Wolfram,

I am asking as this patch should be considered as a fix, which needs to be
applied to the 5.15 kernel itself if possible (now or via stable), as we are
implementing a new mandatory feature, which will make the currently merged
version of the driver unusable going forward (since this won't be backwards
compatible).

-- 
viresh