On Fri, Dec 21, 2012 at 12:28:38PM +0800, Peter Chen wrote: > On Tue, Dec 18, 2012 at 11:11:15AM -0500, Alan Stern wrote: > > I suggest that we remove the CONFIG_USB_SUSPEND option, starting in > > 3.9. Practically everyone enables it, and the amount of code it > > protects is fairly small (just portions of usbcore, nothing in the > > drivers). > > > > Basically, if people don't want their kernels to save power then they > > should turn off CONFIG_PM. > > > > Objections, anyone? > Sorry, I may not agree with this due to below reasons: > > - Some customers wants system PM, but do not want usb runtime power > management, such as Car Navigation System. They want system > responds fast after user press power on key, but they don't care > usb power during runtime. What is "fast"? And you can always explicitly keep the device away by writing to the proper sysfs file, right? And this isn't always true from all automotive systems, some that I talk to in that industry do need this, as they are not allowed to drain a lot of power all the time (think about when running on a car battery), and their power budget is quite low. > - For embedded system, we have may SoCs, and USB low power mode > is the most challenge job when we bring up new USB module, usually, > our develop sequence like: basic USB functions --> USB function after > System suspend/resume --> USB Runtime PM. We usually disable USB > runtime PM at first. So you need to get this working properly for your devices, what's wrong with that? :) thanks, greg k-h -- 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
