MacBook users: possible fix for the SMP problem

[John Baldwin]

On Friday 09 November 2007 06:40:48 am Rui Paulo wrote:
> On 7 Nov 2007, at 21:48, Scott Long wrote:
> 
> > Rui Paulo wrote:
> >> On Nov 7, 2007 7:50 PM, Maxim Sobolev <sobomax at freebsd.org> wrote:
> >>> I don't really like the fact that it has to be turned on manually.  
> >>> Is it
> >>> possible to make this automatic based on BIOS Id or something like  
> >>> this?
> >> Yes, I can turn this on for MacBooks.
> >
> > Yeah, at least have it on by default for the systems that we know have
> > the problem.  I still think that it needs wider application, but as  
> > long
> > as the immediate and identifiable issue is addressed, I'm happy.
> 
> 
> Ok, if there are no objections, I plan to request approval from my  
> mentor and from re@ for the following patch:
> 
> Index: clock.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/isa/clock.c,v
> retrieving revision 1.240
> diff -u -p -r1.240 clock.c
> --- clock.c	26 Oct 2007 03:23:54 -0000	1.240
> +++ clock.c	9 Nov 2007 11:34:56 -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 +619,31 @@ i8254_init(void)
>   void
>   startrtclock()
>   {
> +	char *ichenv, *sysenv;
>   	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");
> +	sysenv = getenv("smbios.system.product");
> +	if ((ichenv !=  NULL) || (sysenv != NULL &&
> +	    strncmp(sysenv, "MacBook", 7) == 0)) {
> +		if (bootverbose)
> +			printf("Disabling LEGACY_USB_EN bit on Intel ICH.\n");
> +		outl(ICH_PMBASE + 0x30, inl(ICH_PMBASE + 0x30) & ~0x8);
> +		if (ichenv)
> +			freeenv(ichenv);
> +		if (sysenv)
> +			freeenv(sysenv);
> +	}
> +	

This is missing a freeenv(sysenv) in the case that ichenv is NULL and 
sysenv != "MacBook".  Perhaps move the freeenv()'s out of the if statement.

-- 
John Baldwin