Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Thu, 26 Oct 2023 10:03:52 +0200 | Subject | Re: [PATCH] clk: clk-conf: bypass setting rate/parent if already same |
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Hi Peng,
On Thu, Oct 26, 2023 at 10:01 AM Peng Fan <peng.fan@nxp.com> wrote: > > Subject: Re: [PATCH] clk: clk-conf: bypass setting rate/parent if already same > > On Thu, Oct 26, 2023 at 8:35 AM Peng Fan (OSS) <peng.fan@oss.nxp.com> > > wrote: > > > From: Peng Fan <peng.fan@nxp.com> > > > > > > If the original rate and parent is already the same as what users > > > wanna to configure through assigned clock rate and parent, there is no > > > need to configure them again which may cause more cpu cycles or more > > > SCMI RPC calls. > > > > > > So check the rate and parent first, and bypass when the original rate > > > and parent are same as requested by device tree node. > > > > > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > /** > > * clk_get_rate - obtain the current clock rate (in Hz) for a clock source. > > * This is only valid once the clock source has been enabled. > > * @clk: clock source > > */ > > > > So at least the second part is not guaranteed to work? > > I am not sure, but seems there is no clk enabled check in clk_get_rate > function.
There is indeed no such check. On most hardware, clk_get_rate() works fine when the clock is disabled, but that is not guaranteed to work everywhere.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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