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: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 12c88c5..cfa9ed1 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -832,6 +832,21 @@
}
#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
@@ -863,6 +878,13 @@
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);