Messages in this thread | | | Date | Sun, 14 Feb 2016 15:51:56 +0100 | Subject | Re: [PATCH v42 5/6] clk: clk_put WARNs if user has not disabled clk | From | Geert Uytterhoeven <> |
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Hi Stephen, Mike,
On Sat, Feb 13, 2016 at 2:18 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: > On 02/11, Michael Turquette wrote: >> >From the clk_put kerneldoc in include/linux/clk.h: >> >> """ >> Note: drivers must ensure that all clk_enable calls made on this clock >> source are balanced by clk_disable calls prior to calling this function. >> """ >> >> The common clock framework implementation of the clk.h api has per-user >> reference counts for calls to clk_prepare and clk_disable. As such it >> can enforce the requirement to properly call clk_disable and >> clk_unprepare before calling clk_put. >> >> Because this requirement is probably violated in many places, this patch >> starts with a simple warning. Once offending code has been fixed this >> check could additionally release the reference counts automatically. > > Do we have any fixes for pm code in the works? I'm worried we're > going to be giving a warning and nobody will fix them or has a > plan to fix them. drivers/base/power/clock_ops.c AFAIK not.
I've been running with the above patch for several months, and I had to remove the two clk_put() calls in {en,dis}able_clock() in drivers/base/power/clock_ops.c to get rid of the warnings when using the legacy clock domain.
Fixing drivers/base/power/clock_ops.c is non-trivial though, as you need a place to store the clk's reference obtained in enable_clock(), for later use in disable_clock().
However, the plan is to make CONFIG_PM=y mandatory for Renesas ARM SoCs with clock domains, which makes us no longer users of the legacy clock domain.
Legacy SH and Davinci/Keystone/OMAP1 users may care, though...
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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