On Tue, Jul 26, 2011 at 11:59:56AM +0200, Oliver Neukum wrote: > Am Dienstag, 26. Juli 2011, 11:44:01 schrieben Sie: > > Le Tue, 26 Jul 2011 16:57:29 +0800, > > Ming Lei <tom.leiming@xxxxxxxxx> a écrit : > > > > > But what Thomas is wanting is that the max power provided by > > > individual port in root hub can be customized, which is not supported > > > by current kernel, but looks like not difficult to do it. > > > > No, I want to set a global power budget for both ports that are on > > the root hub of my platform. I have a max budget of 700 mA for both > > ports, so I can accept one 500 mA device on one port and another 200 mA > > device on another port, but not two 500 mA devices. > > These requirements are identical in consequence. > So you have a budget per hub of 700mA, which translates > into 500mA per port (limit from the spec) > But as soon as you configure a device to actually use > 500mA the limit per port would have to drop to 200mA, correct? from what I understood, 700mA is for the whole thing, so if he configures a 500mA on port A, port B only has 200mA to spare. If he configures a 400mA on port B, port A has only 300mA to spare. Thomas ? -- balbi
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