Messages in this thread Patch in this message | | | Date | Wed, 12 Sep 2007 12:17:58 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | [PATCH] free_irq(): Actually handle DEBUG_SHIRQ |
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Code used for DEBUG_SHIRQ in free_irq() is unreachable -- the for() loop within never terminates otherwise than by return. This is an obvious fix.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> --- Please apply.
While at it, I have a question about the complementary code within request_irq(): when the option in question is enabled, a spurious IRQ is posted before internal setup is done by setup_irq(). This includes the ->depth counter. Now if the interrupt handler of some driver calls disable_irq_nosync(), then code in setup_irq() will mess up the state of ->depth afterwards if this is the first handler being installed (i.e. within the "if (!shared)" block). This is reported later on when enable_irq() called by the driver, by means of a message like this:
Unbalanced enable for IRQ 34 WARNING: at kernel/irq/manage.c:158 enable_irq()
Now given DEBUG_SHIRQ is a debug facility, not to be normally used for production, is the phenomenon as described considered a design limitation we can live with, or is it a bug that qualifies for a fix?
I can reproduce this problem easily with phylib.
Maciej
patch-mips-2.6.23-rc5-20070904-debug-shirq-0 diff -up --recursive --new-file linux-mips-2.6.23-rc5-20070904.macro/kernel/irq/manage.c linux-mips-2.6.23-rc5-20070904/kernel/irq/manage.c --- linux-mips-2.6.23-rc5-20070904.macro/kernel/irq/manage.c 2007-09-04 04:56:21.000000000 +0000 +++ linux-mips-2.6.23-rc5-20070904/kernel/irq/manage.c 2007-09-11 23:58:59.000000000 +0000 @@ -448,7 +448,7 @@ void free_irq(unsigned int irq, void *de if (action->flags & IRQF_SHARED) handler = action->handler; kfree(action); - return; + break; } printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq); spin_unlock_irqrestore(&desc->lock, flags); - 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/
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