On Tue, Feb 08, 2005 at 10:20:04AM -0800, Matthew Dharm wrote: > On Tue, Feb 08, 2005 at 10:03:47AM +0100, Andi Kleen wrote: > > On Mon, Feb 07, 2005 at 04:02:44PM -0800, Matthew Dharm wrote: > > > On Tue, Feb 08, 2005 at 12:19:19AM +0100, Andi Kleen wrote: > > > > Remove useless AMD 8111 EHCI USB 2.0 errata check. The BIOS disable it > > > > anyways > > > > when needed, and when not then the hardware works. This cleans up > > > > the EHCI driver a bit which shouldn't need to know about such Erratas. > > > > > > > > Signed-off-by: Andi Kleen <[EMAIL PROTECTED]> > > > > > > This is not a valid assertion. The IBM 970FX Evaluation Platform (aka > > > Maple-D) has an 8111 but does _not_ have an x86 BIOS. So the device tree > > > is built from a normal PCI-scan (unlike x86 BIOS which passes an explicit > > > tree). That device tree therefore shows the device. > > > > That sounds like a firmware bug then. Perhaps it would be better > > to fix the firmware than to add these workarounds to Linux code? > > We've tried. AMD tells us that there is no way to physically disable the > controller. So, Linux will see it when it does a PCI scan. There's > nothing the firmware can do about this.
They told you wrong then. There is definitely a disable bit for it. > > But there are valid reasons in some cases to want to have EHCI > > even on a 8111, e.g. if you want to use the debug port. It's annoying > > to have to fight against such dumb code in the kernel then. > > The official errata from AMD says "don't use EHCI". There's no indication > that it works under any circumstances. No, the errata says "don't use USB2.0". There is some design bug in the 2.0 handling. EHCI with USB 1.x works just fine. Disabling EHCI is merely a way to disable use of 2.0, but it has drawbacks if you want to use other features of EHCI. -Andi ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
