[BUG][RFC] [GENERIC IRQ] irq_chip_set_defaults shutdown / disable

From: Hennerich, Michael
Date: Mon Feb 18 2008 - 11:58:23 EST


RESENT: Add Maintainers

free_irq() does not disable/mask the irq, in case disable or shutdown in struct irq_chip is left uninitilazied.

/**
* struct irq_chip - hardware interrupt chip descriptor
*
* @name: name for /proc/interrupts
* @startup: start up the interrupt (defaults to ->enable if NULL)
* @shutdown: shut down the interrupt (defaults to ->disable if NULL)
* @enable: enable the interrupt (defaults to chip->unmask if NULL)
* @disable: disable the interrupt (defaults to chip->mask if NULL)


According to linux/irq.h struct irq_chip information,
chip->disable should default to chip->mask if NULL.
However irq_chip_set_defaults(struct irq_chip *chip) will set it to default_disable an empty function.

In earlier kernel versions such as 2.6.19 default_disable called chip->mask.
In 2.6.22 and 2.6.24 default_disable is an empty function.

Looking through various architectures, it's still pretty common that disable and shutdown is NULL.

Do I miss something here?

Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>

Index: irq/chip.c
===================================================================
--- irq/chip.c (revision 4276)
+++ irq/chip.c (working copy)
@@ -233,6 +233,10 @@
*/
static void default_disable(unsigned int irq) {
+ struct irq_desc *desc = irq_desc + irq;
+
+ desc->chip->mask(irq);
+ desc->status |= IRQ_MASKED;
}

/*

Best regards,
Michael

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