[PATCH] libata: set IRQF_SHARED for legacy PCI IDE IRQs

[PATCH] libata: set IRQF_SHARED for legacy PCI IDE IRQs

[Tejun Heo]

There are machines out there which share legacy PCI IDE IRQs w/ other
devices.  libata SFF interrupt/HSM code is ready for shared IRQ and
has been setting IRQF_SHARED for devices in native PCI mode.  Device
in legacy mode is still a PCI device and thus supposedly uses
active-low level triggered IRQ.

Machines with such setup should be quite rare and w/o this flag libata
is likely to fail loading and render the system unuseable.  Also, IDE
driver has been setting IRQF_SHARED for devices in legacy mode for a
looooong time.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---

Jeff, I couldn't find a generic way to check whether an IRQ is
confiured as level or edge.  All these legacy mess are pretty much for
the BIOS to figure out, so let's just do what IDE has been doing.

Thanks.

 drivers/ata/libata-sff.c |    1 +
 1 file changed, 1 insertion(+)

Index: work/drivers/ata/libata-sff.c
===================================================================
--- work.orig/drivers/ata/libata-sff.c
+++ work/drivers/ata/libata-sff.c
@@ -911,6 +911,7 @@ static struct ata_probe_ent *ata_pci_ini
 		return NULL;
 
 	probe_ent->n_ports = 2;
+	probe_ent->irq_flags = IRQF_SHARED;
 
 	if (port_mask & ATA_PORT_PRIMARY) {
 		probe_ent->irq = ATA_PRIMARY_IRQ;

Re: [PATCH] libata: set IRQF_SHARED for legacy PCI IDE IRQs

[Jeff Garzik]

Tejun Heo wrote:
> There are machines out there which share legacy PCI IDE IRQs w/ other
> devices.  libata SFF interrupt/HSM code is ready for shared IRQ and
> has been setting IRQF_SHARED for devices in native PCI mode.  Device
> in legacy mode is still a PCI device and thus supposedly uses
> active-low level triggered IRQ.
> 
> Machines with such setup should be quite rare and w/o this flag libata
> is likely to fail loading and render the system unuseable.  Also, IDE
> driver has been setting IRQF_SHARED for devices in legacy mode for a
> looooong time.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> ---
> 
> Jeff, I couldn't find a generic way to check whether an IRQ is
> confiured as level or edge.  All these legacy mess are pretty much for
> the BIOS to figure out, so let's just do what IDE has been doing.
> 
> Thanks.

ACK

probably appropriate for #upstream-fixes, but IMO it's too late into -rc 
to apply such a change without wide testing