Anton Vorontsov wrote: 
When no irq specified, pata_of_platform fills irq_res with -1,
which is wrong to do for two reasons:

1. By definition, 'no irq' should be IRQ 0, not some negative integer;
2. pata_platform checks for irq_res.start > 0, but since irq_res.start
   is unsigned type, the check will be true for `-1'.

Reported-by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---

Thanks!  Your fix is better - I didn't really like the -1 stuff.

I found this bug because I had to disable the ATA interrupt on my system in order to get a compact-flash card to work.  I am still trying to find out why the interrupt doesn't work for me.  Here is part of the console log with the interrupt enabled:
Uniform Multi-Platform E-IDE driver
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
Driver 'sd' needs updating - please use bus_type methods
irq: irq_create_mapping(0xc0574900, 0x1b)
irq: -> using host @c0574900
irq: -> obtained virq 32
scsi0 : pata_platform
ata1: PATA max PIO4 mmio cmd 0x1c1000000 ctl 0x1c1000080 irq 32
irq 32: nobody cared (try booting with the "irqpoll" option)
Call Trace:
[cf83fcc0] [c0005a64] show_stack+0x44/0x1ac (unreliable)
[cf83fd00] [c00489e4] __report_bad_irq+0x34/0xb8
[cf83fd20] [c0048cf0] note_interrupt+0x288/0x2d0
[cf83fd50] [c0049a94] handle_level_irq+0xac/0x114
[cf83fd60] [c0003df0] do_IRQ+0xa4/0xc8
[cf83fd70] [c000d60c] ret_from_except+0x0/0x18
[cf83fe30] [00000020] 0x20
[cf83fe50] [c0003d48] do_softirq+0x54/0x58
[cf83fe60] [c00241c0] irq_exit+0x90/0x94
[cf83fe70] [c0003df4] do_IRQ+0xa8/0xc8
[cf83fe80] [c000d60c] ret_from_except+0x0/0x18
[cf83ff40] [c01b2cc0] ata_pio_task+0x48/0x104
[cf83ff60] [c00307a0] run_workqueue+0xb8/0x148
[cf83ff90] [c0030d54] worker_thread+0x70/0xd0
[cf83ffd0] [c0034788] kthread+0x48/0x84
[cf83fff0] [c000cd6c] kernel_thread+0x44/0x60
handlers:
[<c01b2d7c>] (ata_sff_interrupt+0x0/0x234)
Disabling IRQ #32

So it looks like the ATA handler was attached - not sure yet why I got the "nobody cared" message.  Also, the system hangs.  If I find something, I'll post it.

    Steve