Re: [PATCH v3 7/7] i2c: bcm2835: Add support for dynamic clock

From: Noralf TrÃnnes
Date: Wed Sep 28 2016 - 18:10:57 EST

Den 28.09.2016 23:24, skrev Eric Anholt:
Noralf TrÃnnes <noralf@xxxxxxxxxxx> writes:

Support a dynamic clock by reading the frequency and setting the
divisor in the transfer function instead of during probe.
Is this fixing some particular case you could note in the commit
message? As is, it makes me think that we should be using a notifier
for when the parent clock (that's the one I assume you're talking about
being dynamic) changes. But maybe you're working around a variable VPU
clock being set by the firmware, because we don't have a notifier for

I'm a bit worried because I think this is going to be pretty expensive
to be doing per transfer.

Actually I thought that this was a known problem, but trying to track
it down now, I can't find anything definitive. I don't have any tool
to look at the bus signals, so I couldn't actually test it.
Sorry about this, we can just drop this patch.