On 06/03/12 23:14, Rafael J. Wysocki wrote: > On Tuesday, March 06, 2012, Guennadi Liakhovetski wrote: >> On Tue, 6 Mar 2012, Adrian Hunter wrote: >> >>> On 04/03/12 02:01, Rafael J. Wysocki wrote: >>>> Hi all, >>>> >>>> The goal of this patchset is to allow user space to control the >>>> responsiveness of the MMC stack related to runtime power management. >>> >>> I wonder why this is build into mmc and not just a generic runtime pm >>> facility. e.g. > > Because of the user space interface (it doesn't necessarily make sense > for all devices) and to allow drivers to opt-in (if they don't, the interface > won't be created), which is not possible at the core level (we don't know in > advance what drivers will handle the given devices and if they will support > PM QoS). Even "opt-in" is undesirable, because it is really up to userspace not the driver. > >>> /* Set maximum resume latency target to 100ms */ >>> pm_runtime_set_max_latency(dev, 100); >>> >>> And then runtime pm will create sysfs attributes etc >> >> +1. Having to do essentially exactly the same for each driver subsystem >> seems counterproductive. > > Other subsystems need not do that in the same way. Maybe this needs to be re-thought. Userspace needs a simple, consistent and understandable set of pm controls across the entire kernel, not piecemeal across different subsystems. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
