[PATCH] libata-sff: PCI IRQ handling fix

[PATCH] libata-sff: PCI IRQ handling fix

[Alan Cox]

It is legitimate (although annoying and silly) for a PCI IDE controller
not to be assigned an interrupt and to be polled. The libata-sff code
should therefore not try and request IRQ 0 in this case.

Signed-off-by: Alan Cox <alan@redhat.com>

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.24-rc6-mm1/drivers/ata/libata-sff.c linux-2.6.24-rc6-mm1/drivers/ata/libata-sff.c
--- linux.vanilla-2.6.24-rc6-mm1/drivers/ata/libata-sff.c	2008-01-02 16:04:19.000000000 +0000
+++ linux-2.6.24-rc6-mm1/drivers/ata/libata-sff.c	2008-01-02 16:12:39.000000000 +0000
@@ -808,7 +808,10 @@
 	if (rc)
 		goto err_out;
 
-	if (!legacy_mode) {
+	if (!legacy_mode && pdev->irq) {
+		/* We may have no IRQ assigned in which case we can poll. This
+		   shouldn't happen on a sane system but robustness is cheap
+		   in this case */
 		rc = devm_request_irq(dev, pdev->irq, pi->port_ops->irq_handler,
 				      IRQF_SHARED, DRV_NAME, host);
 		if (rc)
@@ -816,7 +819,7 @@
 
 		ata_port_desc(host->ports[0], "irq %d", pdev->irq);
 		ata_port_desc(host->ports[1], "irq %d", pdev->irq);
-	} else {
+	} else if (legacy_mode) {
 		if (!ata_port_is_dummy(host->ports[0])) {
 			rc = devm_request_irq(dev, ATA_PRIMARY_IRQ(pdev),
 					      pi->port_ops->irq_handler,
 

Re: [PATCH] libata-sff: PCI IRQ handling fix

[Tejun Heo]

Alan Cox wrote:
> It is legitimate (although annoying and silly) for a PCI IDE controller
> not to be assigned an interrupt and to be polled. The libata-sff code
> should therefore not try and request IRQ 0 in this case.
> 
> Signed-off-by: Alan Cox <alan@redhat.com>
> 
> diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.24-rc6-mm1/drivers/ata/libata-sff.c linux-2.6.24-rc6-mm1/drivers/ata/libata-sff.c
> --- linux.vanilla-2.6.24-rc6-mm1/drivers/ata/libata-sff.c	2008-01-02 16:04:19.000000000 +0000
> +++ linux-2.6.24-rc6-mm1/drivers/ata/libata-sff.c	2008-01-02 16:12:39.000000000 +0000
> @@ -808,7 +808,10 @@
>  	if (rc)
>  		goto err_out;
>  
> -	if (!legacy_mode) {
> +	if (!legacy_mode && pdev->irq) {
> +		/* We may have no IRQ assigned in which case we can poll. This
> +		   shouldn't happen on a sane system but robustness is cheap
> +		   in this case */
>  		rc = devm_request_irq(dev, pdev->irq, pi->port_ops->irq_handler,
>  				      IRQF_SHARED, DRV_NAME, host);
>  		if (rc)
> @@ -816,7 +819,7 @@
>  
>  		ata_port_desc(host->ports[0], "irq %d", pdev->irq);
>  		ata_port_desc(host->ports[1], "irq %d", pdev->irq);
> -	} else {
> +	} else if (legacy_mode) {

I would prefer to put if (pdev->irq) inside if (!legacy_mode) but that's
nothing major.

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

-- 
tejun

Re: [PATCH] libata-sff: PCI IRQ handling fix

[Jeff Garzik]

Alan Cox wrote:
> It is legitimate (although annoying and silly) for a PCI IDE controller
> not to be assigned an interrupt and to be polled. The libata-sff code
> should therefore not try and request IRQ 0 in this case.
> 
> Signed-off-by: Alan Cox <alan@redhat.com>

applied #upstream-fixes (2.6.24)