Revision c642b8391cf8efc3622cc97329a0f46e7cbb70b8 authored by Russ Anderson on 15 November 2007, 01:00:15 UTC, committed by Linus Torvalds on 15 November 2007, 02:45:43 UTC
In __do_IRQ(), the normal case is that IRQ_DISABLED is checked and if set the handler (handle_IRQ_event()) is not called. Earlier in __do_IRQ(), if IRQ_PER_CPU is set the code does not check IRQ_DISABLED and calls the handler even though IRQ_DISABLED is set. This behavior seems unintentional. One user encountering this behavior is the CPE handler (in arch/ia64/kernel/mca.c). When the CPE handler encounters too many CPEs (such as a solid single bit error), it sets up a polling timer and disables the CPE interrupt (to avoid excessive overhead logging the stream of single bit errors). disable_irq_nosync() is called which sets IRQ_DISABLED. The IRQ_PER_CPU flag was previously set (in ia64_mca_late_init()). The net result is the CPE handler gets called even though it is marked disabled. If the behavior of not checking IRQ_DISABLED when IRQ_PER_CPU is set is intentional, it would be worthy of a comment describing the intended behavior. disable_irq_nosync() does call chip->disable() to provide a chipset specifiec interface for disabling the interrupt, which avoids this issue when used. Signed-off-by: Russ Anderson <rja@sgi.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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crypto | ||
drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
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security | ||
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.gitignore | -rw-r--r-- | 628 bytes |
.mailmap | -rw-r--r-- | 3.6 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 90.1 KB |
Kbuild | -rw-r--r-- | 1.6 KB |
MAINTAINERS | -rw-r--r-- | 93.2 KB |
Makefile | -rw-r--r-- | 52.1 KB |
README | -rw-r--r-- | 16.5 KB |
REPORTING-BUGS | -rw-r--r-- | 3.0 KB |
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