From: Magnus Damm Date: Sat, 3 Feb 2007 09:13:48 +0000 (-0800) Subject: [PATCH] kexec: Avoid migration of already disabled irqs (ia64) X-Git-Tag: v2.6.20~9 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29a002776ba5ef170446910b1f93c480cdd43706;p=linux-2.6 [PATCH] kexec: Avoid migration of already disabled irqs (ia64) This patch fixes up ia64 kexec support for HP rx2620 hardware. It does this by skipping migration of already disabled irqs. This is most likely a problem on other ia64 platforms as well, but I've only been able to reproduce it on one machine so far. The full story is that handle_bad_irq() gets invoked before starting the new kernel without this patch. This seems to happen when fixup_irqs() calls generic_handle_irq() on already migrated (and disabled) irqs. So by avoiding migration of disabled irqs we stay away of handle_bad_irq(). The code has been tested on three different ia64 machines, all with good results. It is possible to trigger the same bug by offlining a processor using echo 0 > /sys/devices/system/cpu/cpuX/online. More detailed information is available in the following mail thread: http://lists.osdl.org/pipermail/fastboot/2007-January/thread.html#5774 Signed-off-by: Magnus Damm Acked-by: Simon Horman Acked-by: Zou, Nanhai Acked-by: Jay Lan Acked-by: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c index 54d55e4d64..ce49c85c92 100644 --- a/arch/ia64/kernel/irq.c +++ b/arch/ia64/kernel/irq.c @@ -122,6 +122,9 @@ static void migrate_irqs(void) for (irq=0; irq < NR_IRQS; irq++) { desc = irq_desc + irq; + if (desc->status == IRQ_DISABLED) + continue; + /* * No handling for now. * TBD: Implement a disable function so we can now