Commit 4112e16a authored by Alan Cox's avatar Alan Cox Committed by Jeff Garzik
Browse files

libata-sff: Don't try and activate channels which are not in use 



An ATA controller in native mode may have one or more channels disabled
and not assigned resources. In that case the existing code crashes trying
to access I/O ports 0-7.

Add the neccessary check.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent d73f30e1

drivers/ata/libata-sff.c

+22 −0
Original line number Diff line number Diff line
@@ -832,6 +832,21 @@ void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc) 
}



#ifdef CONFIG_PCI



static int ata_resources_present(struct pci_dev *pdev, int port)

{

	int i;

	

	/* Check the PCI resources for this channel are enabled */

	port = port * 2;

	for (i = 0; i < 2; i ++) {

		if (pci_resource_start(pdev, port + i) == 0 ||

			pci_resource_len(pdev, port + i) == 0)

		return 0;

	}

	return 1;

}

		

/**

 *	ata_pci_init_native_mode - Initialize native-mode driver

 *	@pdev:  pci device to be initialized
@@ -864,6 +879,13 @@ ata_pci_init_native_mode(struct pci_dev *pdev, struct ata_port_info **port, int 
	probe_ent->irq = pdev->irq;

	probe_ent->irq_flags = IRQF_SHARED;

	

	/* Discard disabled ports. Some controllers show their

	   unused channels this way */

	if (ata_resources_present(pdev, 0) == 0)

		ports &= ~ATA_PORT_PRIMARY;

	if (ata_resources_present(pdev, 1) == 0)

		ports &= ~ATA_PORT_SECONDARY;



	if (ports & ATA_PORT_PRIMARY) {

		probe_ent->port[p].cmd_addr = pci_resource_start(pdev, 0);

		probe_ent->port[p].altstatus_addr =