On Tue, Dec 04, 2012 at 11:40:05AM +0800, Andy Green wrote: > On 04/12/12 01:09, the mail apparently from Alan Stern included: > >On Mon, 3 Dec 2012, Andy Green wrote: > > > >>Unless someone NAKs it for sure already (if you're already sure you're > >>going to, please do so to avoid wasting time), I'll issue a try#2 of my > >>code later which demonstrates what I mean. At least I guess it's useful > >>for comparative purposes. > > > >Before you go writing a whole lot more code, we should discuss the > >basics a bit more clearly. There are several unsettled issues here: > > > 1. Should the LAN95xx stuff be associated with the ehci-omap.0's > > driver or with the hub port? The port would be more flexible, > > offering the ability to turn the power off and on while the > > system is running without affecting anything else. But the > > port code is currently in flux, which could cause this new > > addition to be delayed. > > I think associating ULPI PHY reset and SMSC power and reset with the > hub port power state is good. Then, you could have the driver in a > device with multiple onboard USB devices, and individually control > whether they're eating power or not. In the asset case, you'd > associate mux assets with ehci-omap.0. > > Yesterday I studied the hub port code and have a couple of patches, > one normalizes the hub port device to have a stub driver. > > The other then puts hub port power state signalling into runtime_pm > handlers in the hub port device. Until now, actually there's no > code in hub.c to switch off a port. Did you take a look at the most recent patches from Tianyu to add support to power off a port if a device is suspended? Start of the series: http://marc.info/?l=linux-usb&m=135314427413307&w=2 Patch that adds power off on device suspend: http://marc.info/?l=linux-usb&m=135314431913321&w=2 Tianyu also added some code to the xHCI host controller driver to call into the ACPI methods to power off a port when the USB hub driver clears the port power feature. Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
