hi, list:
I have a question about default_startup() in kernel/irq/chip.c:
/*
* default startup function
*/
static unsigned int default_startup(unsigned int irq)
{
irq_desc[irq].chip->enable(irq);
return 0;
}
By default, default_startup will call irq_chip->enable(), but some
drivers like i8259A, in arch/mips/kenrel/i8259.c:
static struct irq_chip i8259A_chip = {
.name = "XT-PIC",
.mask = disable_8259A_irq,
.disable = disable_8259A_irq,
.unmask = enable_8259A_irq,
.mask_ack = mask_and_ack_8259A,
#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
.set_affinity = plat_set_irq_affinity,
#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
};
which don't initialize irq_chip->enable, in some (probably rare) case
when irq_chip->startup() get called, it will cause NULL pointer
reference. is it OK to change i8259A_chip (add .enable =
xxx_unmask, .disable = xxx_mask) or just change default_startup()
function? (irq_desc[irq].chip->unmask() or so?)
Regards,
Wang
--
Wang, Baojun Lanzhou University
Distributed & Embedded System Lab http://dslab.lzu.edu.cn
School of Information Science and Engeneering wangbj@xxxxxxxxxxxxxxxx
Tianshui South Road 222. Lanzhou 730000 .P.R.China
Tel: +86-931-8912025 Fax: +86-931-8912022
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