Re: [PATCH] USB BIOS early handoff only when the we the driver is configured
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
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 ------------------------------------------------------------------------- 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