linux-kernel - Re: [PATCH v3 01/19] usb: dwc3: enable hibernation if to be supported

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20141028191852.GJ25735@saruman>
Date:	Tue, 28 Oct 2014 14:18:52 -0500
From:	Felipe Balbi <balbi@...com>
To:	Paul Zimmerman <Paul.Zimmerman@...opsys.com>
CC:	"balbi@...com" <balbi@...com>, Huang Rui <ray.huang@....com>,
	Alan Stern <stern@...land.harvard.edu>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
	Jason Chang <jason.chang@....com>,
	Vincent Wan <vincent.wan@....com>, Tony Li <tony.li@....com>,
	"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 01/19] usb: dwc3: enable hibernation if to be supported

On Tue, Oct 28, 2014 at 07:15:29PM +0000, Paul Zimmerman wrote:
> > From: Felipe Balbi [mailto:balbi@...com]
> > Sent: Tuesday, October 28, 2014 12:01 PM
> > 
> > On Tue, Oct 28, 2014 at 06:55:50PM +0000, Paul Zimmerman wrote:
> > > > From: Felipe Balbi [mailto:balbi@...com]
> > > > Sent: Tuesday, October 28, 2014 11:51 AM
> > > >
> > > > On Tue, Oct 28, 2014 at 06:47:08PM +0000, Paul Zimmerman wrote:
> > > > > > From: Huang Rui [mailto:ray.huang@....com]
> > > > > > Sent: Tuesday, October 28, 2014 4:54 AM
> > > > > >
> > > > > > It enables hibernation if the function is set in coreConsultant.
> > > > > >
> > > > > > Suggested-by: Felipe Balbi <balbi@...com>
> > > > > > Signed-off-by: Huang Rui <ray.huang@....com>
> > > > > > ---
> > > > > >  drivers/usb/dwc3/core.c | 1 +
> > > > > >  1 file changed, 1 insertion(+)
> > > > > >
> > > > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > > > > > index fa396fc..bf77509 100644
> > > > > > --- a/drivers/usb/dwc3/core.c
> > > > > > +++ b/drivers/usb/dwc3/core.c
> > > > > > @@ -449,6 +449,7 @@ static int dwc3_core_init(struct dwc3 *dwc)
> > > > > >  	case DWC3_GHWPARAMS1_EN_PWROPT_HIB:
> > > > > >  		/* enable hibernation here */
> > > > > >  		dwc->nr_scratch = DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);
> > > > > > +		reg |= DWC3_GCTL_GBLHIBERNATIONEN;
> > > > > >  		break;
> > > > > >  	default:
> > > > > >  		dev_dbg(dwc->dev, "No power optimization available\n");
> > > > >
> > > > > What effect does this have when the controller is in device mode? I
> > > > > expect it will start generating DWC3_DEVICE_EVENT_HIBER_REQ interrupt
> > > > > events when this register bit is set. So the dev_WARN_ONCE in
> > > > > dwc3_gadget_interrupt() will start firing, I think.
> > > >
> > > > Ok, so this *has* to wait for proper hibernation support ?
> > >
> > > Ah, never mind. Since the hibernation event is not enabled in the
> > > DEVTEN register, the controller shouldn't generate that event after
> > > all. So I think it should be OK. Sorry for the noise.
> > 
> > do you think it's still nice to have a comment here ?
> 
> Maybe something along the lines of "enabling this bit so that host-mode
> hibernation will work, device-mode hibernation is not implemented yet"?

sounds good to me. Huang, can you update your patch to add this comment
Paul suggested ?

thanks

-- 
balbi

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)