On 08/06/2013 04:28 PM, Rafael J. Wysocki wrote: > On Tuesday, August 06, 2013 09:38:36 PM Shuah Khan wrote: >> On 08/06/2013 03:22 PM, Alan Stern wrote: >>> On Tue, 6 Aug 2013, Shuah Khan wrote: >>> >>>> With the dev_pm_ops model, drivers have to provide interfaces for each >>>> one of these states. >>> >>> No, they don't. They can leave out interfaces if they want. >> >> Yes. Agreed. There is no need to provide each and every interface. Only >> the ones driver wishes to handle. >> >>> >>>> In this case, there will be a conflict since >>>> pm_op() treats this state as freeze where as the driver wants to do >>>> treat it as a suspend/hibernate. In the case of legacy pm_ops, state is >>>> passed in as a parameter and driver could take special action if need >>>> be, based on the state, however in dev_pm_ops model, state is not passed >>>> in. Instead it is handled with state specific pm_ops interfaces. >>>> >>>> For example, if this driver were to be converted to dev_pm_ops, it would >>>> require a freeze interface which will call sl811h_bus_suspend(). Once >>>> that is done, PM_EVENT_PRETHAW will be mapped to freeze() ops and >>>> sl811h_bus_suspend() will be called instead of port_power(sl811, 0); >>>> >>>> What I am getting at is, there is no provision to handle the special >>>> case for PM_EVENT_PRETHAW like in the case of this driver when using >>>> dev_pm_ops. >>> >>> Okay. So what? >>> >> >> I am exploring to see if there is a deficiency in dev_pm_ops >> infrastructure that needs addressing. > > No, there isn't. We determined a few years ago that "freeze" could always be > used instead of "prethaw". Moreover, there actually is a "thaw" after that > stage if the image restoration fails, so please just use "freeze" here. Or > just skip it if it is not really needed. >
Thanks Rafael! -- Shuah Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah...@samsung.com | (970) 672-0658 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
