Re: [PATCH] USB BIOS early handoff only when the we the driver is configured
David Engraf <[email protected]>
| Newsgroups | gmane.linux.usb.devel,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
At the moment I have a Jetway/VIA Mainboard which seems to have a problem with the handoff. Evenwhen I wait about 20 seconds the EHCI_USBLEGSUP_BIOS flag is not cleared. I think this is a BIOS bug and I will have to talk to Jetway/VIA. On the other hand, I don't need the EHCI controller in my kernel, so I think the kernel shouldn't take the handover for the EHCI controller like other OS which do not have an usb driver and so don't know that there is a EHCI_USBLEGSUP_BIOS flag which should be cleared. David Engraf Alan Stern schrieb: > On Tue, 31 Jul 2007, David Engraf wrote: > > >> When CONFIG_USB_UHCI_HCD, CONFIG_USB_OHCI_HCD or CONFIG_USB_EHCI_HCD is >> not configured we don't need to call the quirk_usb_handoff_xxxx function >> in driver/usb/host/pci_quiks.c. >> >> I think the kernel shouldn't take the control over the usb controller >> when we don't have the driver for it, >> so with this patch the kernel takes the control only when the driver is >> configured. >> > > Have you found a system where this really improves behavior or is it > just theoretical? > > There _is_ a theoretical reason for running the handoff routines even > when the corresponding driver isn't configured. Namely, at startup the > controller will be in some undetermined state as a result of usage by > the firmware. Resetting it to a known idle state is a good idea. > > Bear in mind that on some systems, not performing the handoff has > caused interrupt storms during startup. > > Alan Stern > > > -- Mit freundlichen Grüßen David Engraf Netcom Sicherheitstechnik GmbH Rheinallee 189 55120 Mainz Tel: +49 6131 6305 0 Fax: +49 6131 6305 40 Email: [email protected] Sitz der Gesellschaft: Mainz Registergericht: Amtsgericht Mainz, 14HRB3411 Geschäftsführer: Peter Otto ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel