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SubjectRe: [PATCH v6 4/5] clk: aspeed: Register gated clocks
On Sat, 2017-12-30 at 09:03 +1100, Benjamin Herrenschmidt wrote:
> On Tue, 2017-12-26 at 17:32 -0800, Stephen Boyd wrote:
> > > I noticed we do have a few i2c based clock drivers... how are they ever
> > > supposed to work ? i2c bus controllers are allowed to sleep and the i2c
> > > core takes mutexes...
> >
> > We have clk_prepare()/clk_unprepare() for sleeping suckage. You
> > can use that, and i2c based clk drivers do that today.
> "suckage" ? Hehe ... the suckage should rather be stuff that cannot
> sleep. Arbitrary latencies and jitter caused by too much code wanting
> to be "atomic" when unnecessary are a bad thing.
> In the case of clocks like the aspeed where we have to wait for a
> rather long stabilization delay, way too long to legitimately do a non-
> sleepable delay with a lock held, do we need to do everything in
> prepare() then ?

BTW. Pls don't hold Joel's patches for this. Without that clk framework
a lot of the aspeed stuff already upstream doesn't actually work
without additional out-of-tree hacks or uboot black magic.

We can sort out the sleeping issues (and possibly move to using prepare
for the clocks that have that delay requirement) via subsequent


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