On 5 Nov 2007, at 18:18, Scott Long wrote: > Rui Paulo wrote: >> On Nov 4, 2007 11:14 PM, Rink Springer <rink_at_freebsd.org> wrote: >>> Hi Rui, >>> >>> On Sun, Nov 04, 2007 at 08:59:28PM +0000, Rui Paulo wrote: >>>> Note: this is still a hack. I'm still thinking about a way to >>>> correctly identify on which systems we need to apply this fix. >>> This indeed looks hackikly - I don't know whether it's possible to >>> distinguish between a 'normal' PC or a MacBook - but if this is not >>> possible, maybe a kernel option is in order? >> It's possible to distinguish between a MacBook and a PeeCee via >> smbios >> vendor strings. >> But what I actually wanted was something more general. >> Regards. > > Turning this on universally should only affect USB keyboard > operation in > KDB early in boot (or if the USB drivers were omitted during boot). Hmm. I was never able to interact with DDB early on boot. Only after USB gets probed. > It sounds like this affects clock calibration on other systems, not > just > Macs. So I'd vote for this being made into a negative option, i.e. > > options ENABLE_ICH_USB_LEGACY > > That'll at least let people boot with a GENERIC kernel and then decide > for themselves if they want it enabled or disabled. It could also be > made into tunable and set via the loader menu, but I'd only advocate > that if there were found to be other side effects that prevented some > users from booting with GENERIC. I think a loader variable is the best way to go. As I really don't know how if this will affect negatively other systems I was planning to produce a patch that does something like: usb_legacy = getenv("hw.ich.usb_legacy"); if (!usb_legacy) usb_legacy = 0; usb_legacy_activated = read_bit_from_SMI_EN; // SMI Control and Enable Register if (usb_legacy_activated && usb_legacy == "0") { disable SMI interrupt with USB; } What do you think? > Anyways, good job figuring this out. Talk about an obscure problem. > Now I don't feel so bad about spending days in vain going line-by-line > through the AP startup code looking for the problem. Well, don't thank me. As I said in the first email, someone else working on NetBSD found this issue, not me. Regards. -- Rui PauloReceived on Mon Nov 05 2007 - 18:26:05 UTC
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