On Wed, Oct 20, 2021 at 12:47:09PM +0200, Viresh Kumar wrote:

On 20-10-21, 12:38, Vincent Whitchurch wrote:

quoted

I don't quite understand how that would be safe since
virtqueue_add_sgs() can fail after a few iterations and all queued
request buffers can have FAIL_NEXT set.  In such a case, we would end up
waiting forever with your proposed change, wouldn't we?

Good point. I didn't think of that earlier.

I think a good simple way of handling this is counting the number of
buffers sent and received. Once they match, we are done. That
shouldn't break anything else I believe.

That could work, but it's not so straightforward since you would have to
introduce locking to prevent races since the final count is only known
after virtio_i2c_prepare_reqs() completes, while the callback could be
called before that.  Please do not hesitate to send out a patch to fix
it that way if that is what you prefer.
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