> -Original Message-
> From: Alan Stern [mailto:st...@rowland.harvard.edu]
> Sent: Friday, October 26, 2012 11:52 AM
> To: Sarah Sharp
> Cc: USB list; Du, Alek; Pan, Jacob jun
> Subject: Re: Hibernation with LPM, was: Re: xhci: LPM issues using Western
> Digital hard
On Tue, 16 Oct 2012, Sarah Sharp wrote:
> > > > In addition to this, I see that ehci-hcd includes some basic support
> > > > for LPM but it doesn't implement the set_usb2_hw_lpm HCD method. It's
> > > > a sort of do-it-yourself approach (and it includes a bunch of bugs).
> > >
> > > Yeah, I thin
On Tue, 16 Oct 2012, Sarah Sharp wrote:
> > Well, we're talking about two different things. Stopping the endpoints
> > comes under the heading of "quiescing", whereas putting a link into U3
> > comes under the heading of "going to low power". FREEZE and PRETHAW
> > require the host controller (a
On Tue, Oct 16, 2012 at 02:42:20PM -0400, Alan Stern wrote:
> On Tue, 16 Oct 2012, Sarah Sharp wrote:
>
> > > Okay. But that still leaves a question: Is it reasonable to call
> > > xhci-hcd's bus_suspend method without first putting all the devices on
> > > the bus into U3? If it is then generic
On Tue, 16 Oct 2012, Sarah Sharp wrote:
> > Okay. But that still leaves a question: Is it reasonable to call
> > xhci-hcd's bus_suspend method without first putting all the devices on
> > the bus into U3? If it is then generic_suspend() can avoid calling
> > usb_port_suspend() for the FREEZE and
On Tue, Oct 16, 2012 at 01:38:06PM -0400, Alan Stern wrote:
> On Tue, 16 Oct 2012, Sarah Sharp wrote:
>
> > > The kernel support we have now for USB-2 LPM doesn't make any sense.
> > > usb_port_suspend() disables LPM before changing the link state out of
> > > L0, and usb_port_resume() enables L
On Tue, 16 Oct 2012, Alan Stern wrote:
> On Tue, 16 Oct 2012, Sarah Sharp wrote:
>
> > > The kernel support we have now for USB-2 LPM doesn't make any sense.
> > > usb_port_suspend() disables LPM before changing the link state out of
> > > L0, and usb_port_resume() enables LPM after changing th
On Tue, 16 Oct 2012, Sarah Sharp wrote:
> > The kernel support we have now for USB-2 LPM doesn't make any sense.
> > usb_port_suspend() disables LPM before changing the link state out of
> > L0, and usb_port_resume() enables LPM after changing the state back to
> > L0.
> >
> > Thus LPM is disab
On Fri, Oct 12, 2012 at 04:07:43PM -0400, Alan Stern wrote:
> On Thu, 11 Oct 2012, Alan Stern wrote:
>
> > On Thu, 11 Oct 2012, Sarah Sharp wrote:
> >
> > > Thinking about this further, USB 2.1 devices need to be brought out of
> > > their low power link state (L1) before they are suspended. Som
On Thu, 11 Oct 2012, Alan Stern wrote:
> On Thu, 11 Oct 2012, Sarah Sharp wrote:
>
> > Thinking about this further, USB 2.1 devices need to be brought out of
> > their low power link state (L1) before they are suspended. Some xHCI
> > host controllers have hardware-driven USB 2.1 LPM, so the dev
On Thu, 11 Oct 2012, Sarah Sharp wrote:
> Thinking about this further, USB 2.1 devices need to be brought out of
> their low power link state (L1) before they are suspended. Some xHCI
> host controllers have hardware-driven USB 2.1 LPM, so the device could
> have been put in L1 before hibernation
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