Hi Greg, On Tue, Mar 04, 2014 at 09:04:58AM -0800, Greg KH wrote: > On Tue, Mar 04, 2014 at 01:50:55PM +0200, Mathias Nyman wrote: > > On 03/03/2014 08:37 PM, Greg KH wrote: > > >On Mon, Mar 03, 2014 at 07:30:17PM +0200, Mathias Nyman wrote: > > >>xHCI driver has its own pci probe function that will call usb_hcd_pci_probe > > >>to register its usb-2 bus, and then continue to manually register the > > >>usb-3 bus. usb_hcd_pci_probe does a pm_runtime_put_noidle at the end and > > >>might thus trigger a runtime suspend before the usb-3 bus is ready. > > > > > >What is the result if that happens? > > > > Crashes. Null pointer dereference in xhci_suspend() when touching > > xhci->shared_hcd before it's initialized. More info here: > > > > http://marc.info/?l=linux-usb&m=138914518219334&w=2 > > > > > > > >Is this a regression from 3.13? Or something new for 3.14? > > > > > > > According to reporter its been around since 3.7 > > > > commit 596d789a211d134dc5f94d1e5957248c204ef850 > > USB: set hub's default autosuspend delay as 0 > > > > But nobody else than the reporter is able to trigger it. > > Then it can wait for 3.15-rc1, and then go back to the stable trees at > that time, right? I'd prefer that as it's not a regression and not > common. > > > >What platform(s) are affected by this? > > > > David, the reporter (added to cc), mentioned > > "This bug happened in a platform with 1 usb3 host controller + 1 usb3 OTG > > controller" run by some Intel internal group > > > > http://marc.info/?l=linux-usb&m=138915969822029&w=2 > > That sounds like a "not shipping platform" to me :) Not quite. You'd find this configuration on Asus T100T. I said "not quite" because I don't think we can run Linux smoothly on it yet. But... > > Please resend this with patches for 3.15-rc1. ...that sounds fine :) Br, David > > 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
