On Wed, May 07, 2014 at 10:25:55AM -0400, Alan Stern wrote: > On Tue, 6 May 2014, Maxime Ripard wrote: > > > From: Boris BREZILLON <boris.brezillon@xxxxxxxxxxxxxxxxxx> > > > > On the Allwinner's A31 SoC the reset line connected to the EHCI IP has to > > be deasserted for the EHCI block to be usable. > > > > Add support for an optional reset controller that will be deasserted on > > power off and asserted on power on. > > > > Signed-off-by: Boris BREZILLON <boris.brezillon@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > Is this really a _reset_ line? That is, when you assert the reset > line, does it actually reset the EHCI controller, or does it merely > leave the controller in a partially powered-down state? It actually resets the whole controller. > The difference is important. During suspend, the controller is > supposed to remember the state of the port connections as well as other > settings. If it doesn't, the controller and all attached USB devices > will have to be reinitialized every time the controller resumes, which > will increase the latency. So you're saying that we should move this to the probe then? Thanks, Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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