linux/kernel/irq, branch v2.6.25

genirq: do not leave interupts enabled on free_irq

2008-02-19T09:43:58Z

The default_disable() function was changed in commit: 76d2160147f43f982dfe881404cfde9fd0a9da21 genirq: do not mask interrupts by default It removed the mask function in favour of the default delayed interrupt disabling. Unfortunately this also broke the shutdown in free_irq() when the last handler is removed from the interrupt for those architectures which rely on the default implementations. Now we can end up with a enabled interrupt line after the last handler was removed, which can result in spurious interrupts. Fix this by adding a default_shutdown function, which is only installed, when the irqchip implementation does provide neither a shutdown nor a disable function. [@stable: affected versions: .21 - .24 ] Pointed-out-by: Michael Hennerich Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Cc: stable@kernel.org Tested-by: Michael Hennerich

genirq: spurious.c: use time_* macros

2008-02-19T09:43:58Z

The functions time_before, time_before_eq, time_after, and time_after_eq are more robust for comparing jiffies against other values. So following patch implements usage of the time_after() macro, defined at linux/jiffies.h, which deals with wrapping correctly Signed-off-by: S.Caglar Onur Acked-by: Ingo Molnar Signed-off-by: Thomas Gleixner

IRQ_NOPROBE helper functions

2008-02-08T17:22:42Z

Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq method may crash the system because handle_percpu_irq does not check IRQ_WAITING. This for example hits the MIPS Qemu configuration. This patch provides two helper functions set_irq_noprobe and set_irq_probe to set rsp. clear the IRQ_NOPROBE flag. The only current caller is MIPS code but this really belongs into generic code. As an aside, interrupt probing these days has become a mostly obsolete if not dangerous art. I think Linux interrupts should be changed to default to non-probing but that's subject of this patch. Signed-off-by: Ralf Baechle Acked-and-tested-by: Rob Landley Cc: Alan Cox Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel: remove fastcall in kernel/*

2008-02-08T17:22:31Z

[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

genirq: stackdump after the "Trying to free already-free IRQ" message

2008-01-30T12:33:24Z

these bugs are harder to find than they seem, a stackdump helps. make it dependent on CONFIG_DEBUG_SHIRQ so that people can turn it off if it annoys them. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner

x86: add /proc/irq/*/spurious to dump the spurious irq debugging state

2008-01-30T12:32:48Z

This is useful to debug problems with interrupt handlers that return sometimes IRQ_NONE. Signed-off-by: Andi Kleen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner

genirq: turn irq debugging options into module params

2008-01-30T12:32:48Z

This allows to change them at runtime using sysfs. No need to reboot to set them. I only added aliases (kernel.noirqdebug etc.) so the old options still work. Signed-off-by: Andi Kleen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner

genirq: revert lazy irq disable for simple irqs

2007-12-18T17:05:58Z

In commit 76d2160147f43f982dfe881404cfde9fd0a9da21 lazy irq disabling was implemented, and the simple irq handler had a masking set to it. Remy Bohmer discovered that some devices in the ARM architecture would trigger the mask, but never unmask it. His patch to do the unmasking was questioned by Russell King about masking simple irqs to begin with. Looking further, it was discovered that the problems Remy was seeing was due to improper use of the simple handler by devices, and he later submitted patches to fix those. But the issue that was uncovered was that the simple handler should never mask. This patch reverts the masking in the simple handler. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Acked-by: Russell King

__do_IRQ does not check IRQ_DISABLED when IRQ_PER_CPU is set

2007-11-15T02:45:43Z

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 Cc: "Luck, Tony" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Bjorn Helgaas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Fix synchronize_irq races with IRQ handler

2007-10-23T16:01:31Z

As it is some callers of synchronize_irq rely on memory barriers to provide synchronisation against the IRQ handlers. For example, the tg3 driver does tp->irq_sync = 1; smp_mb(); synchronize_irq(); and then in the IRQ handler: if (!tp->irq_sync) netif_rx_schedule(dev, &tp->napi); Unfortunately memory barriers only work well when they come in pairs. Because we don't actually have memory barriers on the IRQ path, the memory barrier before the synchronize_irq() doesn't actually protect us. In particular, synchronize_irq() may return followed by the result of netif_rx_schedule being made visible. This patch (mostly written by Linus) fixes this by using spin locks instead of memory barries on the synchronize_irq() path. Signed-off-by: Herbert Xu Acked-by: Benjamin Herrenschmidt Signed-off-by: Linus Torvalds