On Tue, 2012-06-26 at 17:47 -0700, Mike Turquette wrote: > On 20120625-16:14, Tomi Valkeinen wrote: > > A question about clk_prepare/unprepare, not directly related: let's say > > I have a driver for some HW block. The driver doesn't use clk functions, > > but uses runtime PM. The driver also sets pm_runtime_irq_safe(). > > > > Now, the driver can call pm_runtime_get_sync() in an atomic context, and > > this would lead to the underlying framework (hwmod, omap_device, I don't > > know who =) enabling the func clock for that HW. But this would happen > > in atomic context, so the underlying framework can't use clk_prepare. > > > > How does the underlying framework handle that case? (sorry if that's a > > stupid question =). > > > > I think it's a good question! > > If we're going to call clk_prepare_enable from within a runtime pm > callback then I think we'll need to check if _irq_safe() is set and > conditionally call only clk_enable in such a case. > > I'm not a runtime pm expert, but if the driver owns the responsibility > of calling pm_runtime_irq_safe then the driver has the proper context > to know that it should call clk_prepare BEFORE calling > pm_runtime_get_sync. That's not quite what I meant. If it's the driver that does clk_enable, be it in runtime PM callback or not, it's driver's responsibility. But some clocks are not handled by the driver, but the hwmod/omap_device framework. Mainly I think this is for the functional and interface clocks. The driver has no visibility to those, they are implicitly enabled via pm_runtime_get. Tomi
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