ata: sata_mv: check for errors when parsing nr-ports from dt

If the nr-ports property is missing ata_host_alloc_pinfo is called with
n_ports = 0. This results in host->ports[0] = NULL which later makes
mv_init_host() oops when dereferencing this pointer.

Instead be a bit more cooperative and fail the probing with an error
message.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index efc48bf89d51..823e938c9a78 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -4090,7 +4090,20 @@ static int mv_platform_probe(struct platform_device *pdev)
 
         /* allocate host */
         if (pdev->dev.of_node) {
-                of_property_read_u32(pdev->dev.of_node, "nr-ports", &n_ports);
+                rc = of_property_read_u32(pdev->dev.of_node, "nr-ports",
+                                           &n_ports);
+                if (rc) {
+                        dev_err(&pdev->dev,
+                                "error parsing nr-ports property: %d\n", rc);
+                        return rc;
+                }
+
+                if (n_ports <= 0) {
+                        dev_err(&pdev->dev, "nr-ports must be positive: %d\n",
+                                n_ports);
+                        return -EINVAL;
+                }
+
                 irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
         } else {
                 mv_platform_data = dev_get_platdata(&pdev->dev);