Date: Wed, 7 Nov 2007 15:30:08 +0000 From: Rui Paulo <rpaulo@FreeBSD.org> To: Scott Long <scottl@samsco.org>, Rink Springer <rink@freebsd.org>, freebsd-hardware@freebsd.org, freebsd-current@freebsd.org, freebsd-i386@FreeBSD.org Subject: Re: MacBook users: possible fix for the SMP problem Message-ID: <EABAF87E-087E-4E7D-AACA-0DDF8050D485@FreeBSD.org> In-Reply-To: <60C64C73-A019-4C01-85E1-80DF4C76B1AF@freebsd.org> References: <4A5A9C78-22AC-4480-BDEB-A72F6CF472DB@fnop.net> <20071104231422.GA82337@rink.nu> <e1309ba60711041555n72def9fn71de42fcf40bfaa1@mail.gmail.com> <472F5E62.4080406@samsco.org> <60C64C73-A019-4C01-85E1-80DF4C76B1AF@freebsd.org>
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I'm requesting review for the following patch:
Index: sys/i386/isa/clock.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/isa/clock.c,v
retrieving revision 1.240
diff -u -p -r1.240 clock.c
--- sys/i386/isa/clock.c 26 Oct 2007 03:23:54 -0000 1.240
+++ sys/i386/isa/clock.c 7 Nov 2007 15:27:21 -0000
@@ -130,6 +130,9 @@ static u_char rtc_statusb = RTCSB_24HR;
#define ACQUIRED 2
#define ACQUIRE_PENDING 3
+/* Intel ICH register */
+#define ICH_PMBASE 0x400
+
static u_char timer2_state;
static unsigned i8254_get_timecount(struct timecounter *tc);
@@ -616,11 +619,26 @@ i8254_init(void)
void
startrtclock()
{
+ char *ichenv;
u_int delta, freq;
writertc(RTC_STATUSA, rtc_statusa);
writertc(RTC_STATUSB, RTCSB_24HR);
+ /*
+ * On some systems, namely MacBooks, we need to disallow the
+ * legacy USB circuit to generate an SMI# because this can
+ * cause several problems, namely: incorrect CPU frequency
+ * detection and failure to start the APs.
+ */
+ ichenv = getenv("hw.ich.disable_legacy_usb");
+ if (ichenv != NULL) {
+ if (bootverbose)
+ printf("Disabling LEGACY_USB_EN bit on Intel ICH.\n");
+ outl(ICH_PMBASE + 0x30, inl(ICH_PMBASE + 0x30) & ~0x8);
+ freeenv(ichsmi);
+ }
+
freq = calibrate_clocks();
#ifdef CLK_CALIBRATION_LOOP
if (bootverbose) {
If you have a MacBook, you now need to set hw.ich.disable_legacy_usb
on the boot loader prompt or in loader.conf. I decided to go this
route because it seems safer. Imagine the case where there's a port at
the same IO address that has nothing to do with the ICH7. If we tried
to issue the outl() on every system, something bad could happen.
Comments?
Regards.
--
Rui Paulo
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