Title Resolve Issue #112: i2c: Allow buffer less transactions
Description
Please vote Yes if you agree with all of the following.
If you disagree, please vote No.
If you don't have an opinion, please vote Abstain.

I move that:
The TC agrees to resolve the following specification issue:
Issue #112: i2c: Allow buffer less transactions
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The I2C protocol allows zero-length requests with no data, like the
SMBus Quick command, where the command is inferred based on the
read/write flag itself.

In order to allow such a request, allocate another bit,
VIRTIO_I2C_FLAGS_M_RD(1), in the flags to pass the request type, as read
or write. This was earlier done using the read/write permission to the
buffer itself.

This still won't work well if multiple buffers are passed for the same
request, i.e. the write-read requests, as the VIRTIO_I2C_FLAGS_M_RD flag
can only be used with a single buffer.

Coming back to it, there is no need to send multiple buffers with a
single request. All we need, is a way to group several requests
together, which we can already do based on the
VIRTIO_I2C_FLAGS_FAIL_NEXT flag.

Remove support for multiple buffers within a single request.

Add a new feature flag for zero length requests and make it mandatory
for it to be implemented, so we don't need to drag the old
implementation around.

Here is the patch  to update spec:
https://lists.oasis-open.org/archives/virtio-dev/202110/msg00109.html
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The TC accepts the following proposed changes to the specification:
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https://lists.oasis-open.org/archives/virtio-dev/202110/msg00109.html
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The TC agrees to include the above change(s) in specification version(s) "virtio-v1.2-cs01", and future versions of the
specification.

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Ballot Options Ballot has closed
[ ] Yes
[ ] No
[ ] Abstain
Opening Date Thu, Oct 21 2021 6:45 am EDT
Closing Date Thu, Oct 28 2021 6:45 am EDT
Ballot has closed.

Referenced Items

Name Type Date Actions

03659: Resolve Issue #112: i2c: Allow buffer less transactions

Document (Archive)

2021-10-28