Messages in this thread | | | From | "Sverdlin, Alexander" <> | Subject | Re: [PATCH] i2c: lpi2c: cache peripheral clock rate | Date | Thu, 9 Mar 2023 14:54:56 +0000 |
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Hi!
On Thu, 2023-03-09 at 15:37 +0100, Alexander Stein wrote: > From: Alexander Sverdlin <alexander.sverdlin@siemens.com> > > > > One of the reasons to do it is to save some CPU cycles on > > cpu_freq_get() > > under mutex. The second reason if the (false-positive) lockdep > > splat caused > > by the recursive feature of the "prepare_lock" (one clock instance > > is I2C > > peripheral clock and another is pcf85063 RTC as clock provider): > > > > ====================================================== > > WARNING: possible circular locking dependency detected > > 5.15.71+... #1 Tainted: G O > > Which kernel is this? Mainline or downstream vendor kernel?
found and tested on downstream vendor kernel.
[...]
> > > What if the peripheral clock rate changes? I guess a notifier similar > to > 90ad2cbe88c2 ("i2c: imx: use clk notifier for rate changes") should > be added > as well. >
Good point! Thank you for the hint!
-- Alexander Sverdlin Siemens AG www.siemens.com
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