Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 10 Nov 2015 09:18:35 +0100 | Subject | Re: [PATCH 2/2] thermal: rcar_thermal: use pm_runtime_put_sync() | From | Geert Uytterhoeven <> |
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Hi Morimoto-san, Ulf,
On Tue, Nov 10, 2015 at 3:12 AM, Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> wrote: > From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > > It is using pm_runtime_get_sync() on probe(). Let's use > pm_runtime_put_sync() instead of pm_runtime_put(). Otherwise thermal > sensor doesn't work after unbind/re-bind > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > --- > drivers/thermal/rcar_thermal.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c > index 13d01ed..f7cf2d7 100644 > --- a/drivers/thermal/rcar_thermal.c > +++ b/drivers/thermal/rcar_thermal.c > @@ -373,7 +373,7 @@ static int rcar_thermal_remove(struct platform_device *pdev) > thermal_zone_device_unregister(priv->zone); > } > > - pm_runtime_put(dev); > + pm_runtime_put_sync(dev); > pm_runtime_disable(dev); > > return 0;
While I can confirm this fixes the issue, I think this is a bug in the PM core, and thus your patch is merely a workaround.
Morimoto-san: I assume this is a recent regression. Have you tried to bisect?
With a bit more debugging info, this is the difference between the failing and the "fixed" cases:
unbind:
+rcar_thermal e61f0000.thermal: pm_clk_suspend() +renesas-cpg-mssr e6150000.clock-controller: MSTP 522/thermal OFF rcar_thermal e61f0000.thermal: removing from PM domain clock-controller pm_genpd_remove_device: Remove e61f0000.thermal from clock-controller -renesas-cpg-mssr e6150000.clock-controller: MSTP 522/thermal OFF
bind:
rcar_thermal e61f0000.thermal: adding to PM domain clock-controller __pm_genpd_add_device: Add e61f0000.thermal to clock-controller rcar_thermal e61f0000.thermal: Clock thermal con_id (null) managed by runtime PM. -rcar_thermal e61f0000.thermal: thermal sensor was broken +rcar_thermal e61f0000.thermal: pm_clk_resume() +renesas-cpg-mssr e6150000.clock-controller: MSTP 522/thermal ON rcar_thermal e61f0000.thermal: 1 sensor probed
In the failing case, pm_clk_suspend() is not called, and turning off the module clock is thus delayed until removal of the device from the clock domain. But as pm_clk_suspend() wasn't called, the device isn't correctly resumed on rebind, and the module clock is never re-enabled, leading to a failure.
Ulf, what do you think?
Thanks!
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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