Messages in this thread | | | Subject | RE: How to find if BIOS has already enabled the device | Date | Fri, 27 May 2005 18:34:50 -0700 | From | "Aleksey Gorelov" <> |
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>I am trying to trace the root cause of an annoying problem >with a USB Storage >device - > >My laptop's BIOS supports booting from USB devices. I have attached an >external USB HDD to a USB 2.0 port. If I boot Linux with the >HDD attached and >powered on, load of OHCI-HCD module hangs the machine for >around 2 minutes - >after that it recovers and all is fine. I have tried different distros >without luck, but while installing debian, I figured out that the hang >happens after ohci-hcd calls pci_enable_device() for the USB >controller. > >This does not happen when the boot is complete. I.e. if I >attach the HDD after >boot is complete (BIOS did not get a chance to enable it >beforehand) load of >ohci-hcd (during and after boot) does not hang the machine. > >I think since the machine supports booting from USB HDD, the >BIOS must be >enabling the USB controller and attached device early during >boot, and when >ohci-hcd tries to re-enable it, it doesn't like it and leads >to a hang.
See if 'usb-handoff' as a kernel parameter makes it any better.
Aleks.
> >My question - Is it possible to detect if the USB controller >is already >enabled and skip enabling it second time? > >Thanks > >Parag >- >To unsubscribe from this list: send the line "unsubscribe >linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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