lkml.org 
[lkml]   [2002]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectI/O APIC fixed in 2.4.19-pre3 & 2.5.6 (was Re: Linux 2.4.19-pre3)
As a followup, this APIC patch also prevents 2.4 machines on quite a bit
of common hardware from freezing up after a few hours to a few days of
production use. Especially ServerWorks boards distributed by HP and
Rackable/Tyan.

This patch (applied to 2.4.18) seems to fix my long-standing (and
oft-mentioned on LKML) I/O APIC issue with all 2.4 kernels, and I no
longer need my "pintimer" patch to disable the through-8259A mode.

Kudos to the authors -- this was definitely a hard one to find, and I
expect a lot of people will have more stable machines because of it.
I'm also sending this to the folks who helped me with this issue in the
past.

Good work!
--
Ken.
ken@irridia.com

<macro@ds2.pg.gda.pl> (02/03/05 1.466.1.12)
[PATCH] 2.4.18, 2.5.5: I/O APIC through-8259A mode IRQ 0 routing
There is a problem with the through-8259A mode for IRQ 0 on I/O APIC
systems. Depending on correctness of an MP table, IRQ 0 routing is
either not registered at all or registered at a wrong pin. As a result
the 8254 timer IRQ only works by an accident (it's edge-triggered and
never disabled/enabled so it happens to survive this incorrect
configuration). A visible effect is you can't change the affinity for
IRQ 0. Following is a patch that fixes both cases referred to above.
The code looks obvious but it was additionally run-time tested just in
case. The issue is serious -- please apply the patch ASAP. As no
changes were done to io_apic.c since the development fork, the patch
applies cleanly both to 2.4 and to 2.5. Credit goes to Joe for
discovering the affinity problem and providing a fix proposal
(incorporated in the final one). Maciej


On Mon, Mar 11, 2002 at 06:37:46PM -0600, Ken Brownfield wrote:
| Can the authors of this patch post separately on what is fixed here? I
| apply the following patch to work around an eventual hang of the machine
| due to IRQ0 being "attached" to the IO APIC, and I'm hoping that this
| 2.4.19-pre3 patch fixes my problem the correct way. V.s. my workaround
| hack.
|
| Thanks much,
| --
| Ken.
| brownfld@irridia.com
|
| On Mon, Mar 11, 2002 at 06:08:19PM -0300, Marcelo Tosatti wrote:
| | - Fix through-8259A mode for IRQ0 routing on APIC (Maciej W. Rozycki/Joe Korty)
|
|
| --- linux/arch/i386/kernel/io_apic.c.orig Tue Nov 13 17:28:41 2001
| +++ linux/arch/i386/kernel/io_apic.c Tue Dec 18 15:10:45 2001
| @@ -172,6 +172,7 @@
| int pirq_entries [MAX_PIRQS];
| int pirqs_enabled;
| int skip_ioapic_setup;
| +int pintimer_setup;
|
| static int __init ioapic_setup(char *str)
| {
| @@ -179,7 +180,14 @@
| return 1;
| }
|
| +static int __init do_pintimer_setup(char *str)
| +{
| + pintimer_setup = 1;
| + return 1;
| +}
| +
| __setup("noapic", ioapic_setup);
| +__setup("pintimer", do_pintimer_setup);
|
| static int __init ioapic_pirq_setup(char *str)
| {
| @@ -1524,27 +1532,31 @@
| printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC\n");
| }
|
| - printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
| - if (pin2 != -1) {
| - printk("\n..... (found pin %d) ...", pin2);
| - /*
| - * legacy devices should be connected to IO APIC #0
| - */
| - setup_ExtINT_IRQ0_pin(pin2, vector);
| - if (timer_irq_works()) {
| - printk("works.\n");
| - if (nmi_watchdog == NMI_IO_APIC) {
| - setup_nmi();
| - check_nmi_watchdog();
| + if ( pintimer_setup )
| + printk(KERN_INFO "...skipping 8259A init for IRQ0\n");
| + else {
| + printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
| + if (pin2 != -1) {
| + printk("\n..... (found pin %d) ...", pin2);
| + /*
| + * legacy devices should be connected to IO APIC #0
| + */
| + setup_ExtINT_IRQ0_pin(pin2, vector);
| + if (timer_irq_works()) {
| + printk("works.\n");
| + if (nmi_watchdog == NMI_IO_APIC) {
| + setup_nmi();
| + check_nmi_watchdog();
| + }
| + return;
| }
| - return;
| + /*
| + * Cleanup, just in case ...
| + */
| + clear_IO_APIC_pin(0, pin2);
| }
| - /*
| - * Cleanup, just in case ...
| - */
| - clear_IO_APIC_pin(0, pin2);
| + printk(" failed.\n");
| }
| - printk(" failed.\n");
|
| if (nmi_watchdog) {
| printk(KERN_WARNING "timer doesnt work through the IO-APIC - disabling NMI Watchdog!\n");
| -
| To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
| the body of a message to majordomo@vger.kernel.org
| More majordomo info at http://vger.kernel.org/majordomo-info.html
| Please read the FAQ at http://www.tux.org/lkml/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:25    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site