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Date: Thu, 25 Oct 2012 15:13:58 +0200 From: Linus Walleij <linus.walleij@...aro.org> To: Lee Jones <lee.jones@...aro.org> Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, arnd@...db.de, linus.walleij@...ricsson.com, Ulf Hansson <ulf.hansson@...aro.org> Subject: Re: [PATCH 2/6] pinctrl: Update clock handling for the pinctrl-nomadik GPIO driver On Thu, Oct 25, 2012 at 2:41 PM, Linus Walleij <linus.walleij@...aro.org> wrote: > On Wed, Oct 24, 2012 at 4:45 PM, Lee Jones <lee.jones@...aro.org> wrote: > >> The clock framework has changed somewhat and it's now better to >> invoke clock_prepare_enable() and clk_disable_unprepare() rather >> than the legacy clk_enable() and clk_disable() calls. This patch >> converts the Nomadik Pin Control driver to the new framework. >> >> Signed-off-by: Lee Jones <lee.jones@...aro.org> > > I was convinced that this is a good change but no regression, > so applied to the devel branch for 3.8. > > I also removed the initial clk_prepare() so the reference count > may actually go down to 0 for the GPIO block and the peripheral > cluster eventually gets relaxed. Famous last words! The good news is that this actually works, and the refcount *does* go down to zero and gate off entire peripheral clusters. However that was not good because something vital in some peripheral cluster died and killed the system :-D Lee, could to to track down the reason and fix it so the patch can be applied? The only thing you need to do is to remove the superfluous clk_prepare() right after the devm_clk_get() that hogs each peripheral cluster. Probably some driver is needing a clk_get() or a clk_get_sys() is needs to be added somewhere to bring up some vital cluster, or there may be some out-of-tree driver needed to bring up the cluster properly I have no clue... Maybe some cluster just cannot be declocked like that. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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