[PATCH v6 4/5] clk: aspeed: Register gated clocks
From: benh@kernel.crashing.org (Benjamin Herrenschmidt)
Date: 2017-12-29 23:20:55
Also in:
linux-clk, lkml
From: benh@kernel.crashing.org (Benjamin Herrenschmidt)
Date: 2017-12-29 23:20:55
Also in:
linux-clk, lkml
On Tue, 2017-12-26 at 17:32 -0800, Stephen Boyd wrote:
quoted
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 ? Ben.