Re: Fixes for nforce2 hard lockup, apic, io-apic, udma133 covered

[Josh McKinney]

On approximately Sat, Dec 13, 2003 at 10:38:41PM +0100, Ian Kumlien wrote:
> On Sat, 2003-12-13 at 19:07, Ross Dickson wrote:
> > Greetings,
> > I have updated the apic timer ack delay patch and the io-apic edge patch
> > although I do not think anyone had any problems with the first release.
> 
<snip>
> 
> Right now i'm compiling and hope that the patch doesn't need more
> workups. (Josh McKinney patches missed some things, more on that further
> down)
> 
<snip>
> 
> apic part is missing a closing ) and the last part of the #ifdef =)
> So, either rediff or let the users fix that up =)
> 
> -- 
> Ian Kumlien <pomac () vapor ! com> -- http://pomac.netswarm.net

Oops.  I was playing kernel hacker while I should have been doing
other things.  Patch rediffed and both attached.  Thanks for catching
my mess up.

-- 
Josh McKinney		     |	Webmaster: http://joshandangie.org
--------------------------------------------------------------------------
                             | They that can give up essential liberty
Linux, the choice       -o)  | to obtain a little temporary safety deserve 
of the GNU generation    /\  | neither liberty or safety. 
                        _\_v |                          -Benjamin Franklin
diff -urN linux-2.6.0-test11/arch/i386/kernel/io_apic.c linux-2.6.0-test11-nf2/arch/i386/kernel/io_apic.c
--- linux-2.6.0-test11/arch/i386/kernel/io_apic.c	2003-11-26 15:43:32.000000000 -0500
+++ linux-2.6.0-test11-nf2/arch/i386/kernel/io_apic.c	2003-12-13 15:14:25.000000000 -0500
@@ -2128,6 +2128,54 @@
 		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC\n");
 	}
 
+#ifdef CONFIG_ACPI_BOOT && CONFIG_X86_UP_IOAPIC
+        /* for nforce2 try vector 0 on pin0
+         * Note 8259a is already masked, also by default
+         * the io_apic_set_pci_routing call disables the 8259 irq 0
+         * so we must be connected directly to the 8254 timer if this works
+         * Note2: this violates the above comment re Subtle but works!
+         */
+        printk(KERN_INFO "..TIMER: Is timer irq0 connected to IOAPIC Pin0? ...\n");
+        if (pin1 != -1) {
+                extern spinlock_t i8259A_lock;
+                unsigned long flags;
+                int tok, saved_timer_ack = timer_ack;
+                /*
+                 * Ok, does IRQ0 through the IOAPIC work?
+                 */
+                io_apic_set_pci_routing ( 0, 0, 0, 0, 0); /* connect pin */
+                unmask_IO_APIC_irq(0);
+                timer_ack = 0;
+
+                /*
+
+
+
+                 * Ok, does IRQ0 through the IOAPIC work?
+                 */
+                spin_lock_irqsave(&i8259A_lock, flags);
+                Dprintk("..TIMER check 8259 ints disabled, imr1:%02x, imr2:%02x\n", inb(0x21), inb(0xA1));
+                tok = timer_irq_works();
+                spin_unlock_irqrestore(&i8259A_lock, flags);
+                if (tok) {
+                        if (nmi_watchdog == NMI_IO_APIC) {
+                                disable_8259A_irq(0);
+                                setup_nmi();
+                                enable_8259A_irq(0);
+                                check_nmi_watchdog();
+                        }
+                        printk(KERN_INFO "..TIMER: works OK on apic pin0 irq0\n" );
+                        return;
+                }
+                /* failed */
+                timer_ack = saved_timer_ack;
+                clear_IO_APIC_pin(0, 0);
+                io_apic_set_pci_routing ( 0, pin1, 0, 0, 0);
+                printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC Pin 0\n");
+        }
+/* end new stuff for nforce2 */
+#endif
+
 	printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
 	if (pin2 != -1) {
 		printk("\n..... (found pin %d) ...", pin2);
diff -urN linux-2.6.0-test11/arch/i386/kernel/apic.c linux-2.6.0-test11-nf2/arch/i386/kernel/apic.c
--- linux-2.6.0-test11/arch/i386/kernel/apic.c	2003-11-26 15:46:07.000000000 -0500
+++ linux-2.6.0-test11-nf2/arch/i386/kernel/apic.c	2003-12-13 23:48:30.000000000 -0500
@@ -1089,6 +1089,37 @@
 	 */
 	irq_stat[cpu].apic_timer_irqs++;
 
+#ifdef CONFIG_MK7 && CONFIG_BLK_DEV_AMD74XX
+        /*
+         * on 2200XP & nforce2 chipset we need 600ns?
+         * from timer irq start to apic irq ack to prevent
+         * hard lockups, use apic timer itself.
+         * C1 disconnect bit related.  Ross Dickson.
+         */
+        {
+                static unsigned int passno, safecnt;
+                if(!passno) { /* calculate timing */
+                        safecnt = apic_read(APIC_TMICT) -
+                                ( (600UL * apic_read(APIC_TMICT) ) /
+                                (1000000000UL/HZ) );
+                        printk("..APIC TIMER ack delay, reload:%u, safe:%u\n",
+                                apic_read(APIC_TMICT), safecnt);
+                        passno++;
+                }
+#if APIC_DEBUG
+                if(passno<12) {
+                        unsigned int at1 = apic_read(APIC_TMCCT);
+                        if( passno > 1 )
+                                Dprintk("..APIC TIMER ack delay, predelay count:%u \n", at1 );
+                        passno++;
+                }
+# endif
+                /* delay only if required */
+                while( apic_read(APIC_TMCCT) > safecnt )
+                        ndelay(100);
+        }
+#endif
+
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
 	 * because timer handling can be slow.