Hi, On Friday, August 14, 2015 09:37:46 PM Eduardo Valentin wrote: > This change introduces the runtime pm support on imx serial > driver. The objective is to be able to idle the uart > port whenever it is not in use while still being able > to wake it up when needed. The key changes in this patch are: > 1. Move the clock handling to runtime pm. Both, ipg and per, > are now handled in the suspend and resume callbacks. Only > enabling and disabling the clocks are handled in runtime > suspend and resume, so we are able to use runtime pm > in IRQ context. > 2. Clocks are prepared in probe and unprepared in remove, > so we do not need to prepare (may sleep) in runtime pm. > 3. We mark the device activity based on uart and console > callbacks. Whenever the device is needed and we want to > access registers, we runtime_pm_get and then mark its > last usage when we are done. This is done also across > IRQs and DMA callbacks. > 4. We reuse the infrastructure in place for suspend and > resume, so we do not need to redo wakeup configuration, > or context save and restore. > > After this change, the clocks are still sane, in the sense > of having balanced clock prepare and enable. The clock changes in this patch seem to make this driver non-functional with CONFIG_PM=n. Have you tested your changes with CONFIG_PM=n? Generally the driver should not depend on PM support to enable its clocks. We had this issue in few Exynos-specific drivers not that long time ago.. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
