On Mon, 24 Oct 2005, Pete Zaitcev wrote: > On Wed, 19 Oct 2005 12:52:02 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> > wrote: > > > This revised patch (as586b) makes usb-handoff permanently true and no > > longer a kernel boot parameter. [...] > > This looks all right. I thought it was a good thing to do, though > I did not want to get rid of the parameter. BIOSes are so broken, > it's insane. But if you think it should work, then sure, let's give > it a try.
Getting rid of the parameter might have unwanted effects, it's true. On the other hand, it seems silly to keep a parameter that doesn't do anything. I don't know what the standard policy is for this sort of thing. As for BIOSes being broken -- well, this code has to execute at _some_ stage. The only question is whether it runs during PCI device discovery or during USB controller initialization. Making it run as early as possible is the best way to prevent problems from unwanted interrupts. As far as I can tell, the only reason it hasn't always been this way is plain and simple conservatism. Nevertheless, I think it's the right thing to do. Any device that the BIOS leaves running, generating interrupts and doing DMA, is a potential source of trouble unless it can be shut down first thing. (Although it hasn't mattered until recently, there was also a question about whether the handoff code would interfere with system resume, by resetting the device instead of letting it retain its suspended state. Now that the handoff code is under control of the HCD developers, this is no longer an issue.) Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today * Register for a JBoss Training Course Free Certification Exam for All Training Attendees Through End of 2005 Visit http://www.jboss.com/services/certification for more information _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
