On 04/11/2014 05:50 PM, K. Y. Srinivasan wrote:
>
> + /*
> + * Check to see if we have a PIC.
> + * Mask all except the cascade and read
> + * back the value we just wrote. If we don't
> + * have a PIC, we will read 0xff as opposed to the
> + * value we wrote.
> + */
> + outb(probe_val, PIC_MASTER_IMR);
> + probe_val = inb(PIC_MASTER_IMR);
> + if (probe_val == 0xff) {
> + printk(KERN_INFO "Using NULL legacy PIC\n");
> + legacy_pic = &null_legacy_pic;
> + raw_spin_unlock_irqrestore(&i8259A_lock, flags);
> + return;
> + }
> +
> outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
> outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
>
Again, I would do at least the slave masking above the probe.
Also, I would compare to make sure we get the probe_val back and compare
with != instead of comparing with ==.
-hpa
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