Resending with the corrected mailing list Hello Kevin,
I want to draw your attention to an issue the following patch introduces. http://dev.omapzoom.org/?p=swarch/linux-omap-adv.git;a=commitdiff;h=8041359e18e49bf8a3d41f15894db9e476f3a8fc arch/arm/mach-omap2/pm_bus.c patch | blob | history diff --git a/arch/arm/mach-omap2/pm_bus.c b/arch/arm/mach-omap2/pm_bus.c index 9719a9f..5e453dc 100644 (file) --- a/arch/arm/mach-omap2/pm_bus.c +++ b/arch/arm/mach-omap2/pm_bus.c @@ -68,3 +68,51 @@ int platform_pm_runtime_idle(struct device *dev) }; #endif /* CONFIG_PM_RUNTIME */ +#ifdef CONFIG_SUSPEND +int platform_pm_suspend_noirq(struct device *dev) +{ + struct device_driver *drv = dev->driver; + int ret = 0; + + if (!drv) + return 0; + + if (drv->pm) { + if (drv->pm->suspend_noirq) + ret = drv->pm->suspend_noirq(dev); + } + + /* + * The DPM core has done a 'get' to prevent runtime PM + * transitions during system PM. This put is to balance + * out that get so that this device can now be runtime + * suspended. + */ + pm_runtime_put_sync(dev); + + return ret; +} + +int platform_pm_resume_noirq(struct device *dev) +{ + struct device_driver *drv = dev->driver; + int ret = 0; + + /* + * This 'get' is to balance the 'put' in the above suspend_noirq + * method so that the runtime PM usage counting is in the same + * state it was when suspend was called. + */ + pm_runtime_get_sync(dev); + + if (!drv) + return 0; + + if (drv->pm) { + if (drv->pm->resume_noirq) + ret = drv->pm->resume_noirq(dev); + } + + return ret; +} +#endif /* CONFIG_SUSPEND */ I believe, it is not correct to call the pm_runtime APIs from interrupt locked context since the underlying functions __pm_runtime_suspend & __pm_runtime_resume enable interrupts and call schedule(). Further, from a s/w layering standpoint, platform-bus is a deeper layer than the Runtime layer, which the runtime layer calls into. So it may not be correct to have this layer calling into pm_runtime(). It should directly call omap_device APIs. We are facing a similar issue with a few drivers USB, UART & GPIO where, we need to enable/disable clocks & restore/save context in the CPU-Idle path with interrupts locked. As we are unable to use Runtime APIs, we are using omap_device APIs directly with the following modification in the .activate_funcion/ deactivate_funcion (example UART driver) static int uart_idle_hwmod(struct omap_device *od) { if (!irqs_disabled()) omap_hwmod_idle(od->hwmods[0]); else _omap_hwmod_idle(od->hwmods[0]); return 0; } static int uart_enable_hwmod(struct omap_device *od) { if (!irqs_disabled()) omap_hwmod_enable(od->hwmods[0]); else _omap_hwmod_enable(od->hwmods[0]); return 0; } Can you feedback on my observations and comment on the approach taken for these drivers? (We will be posting out the refreshed patches for GPIO, WDT, Timers shortly). Thanks Partha -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
