can: rcar_can: fix IRQ check

rcar_can_probe() regards 0 as a wrong IRQ #, despite platform_get_irq() that it
calls returns negative error code in that case. This leads to the following
being printed to the console when attempting to open the device:

error requesting interrupt fffffffa

because  rcar_can_open() calls request_irq() with a negative IRQ #, and that
function naturally fails with -EINVAL.

Check for the negative error codes instead and propagate them upstream instead
of just returning -ENODEV.

Fixes: fd1159318e55 ("can: add Renesas R-Car CAN driver")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
index 7deb80dcbe8c..93017c09cfc3 100644
--- a/drivers/net/can/rcar_can.c
+++ b/drivers/net/can/rcar_can.c
@@ -758,8 +758,9 @@ static int rcar_can_probe(struct platform_device *pdev)
         }
 
         irq = platform_get_irq(pdev, 0);
-        if (!irq) {
+        if (irq < 0) {
                 dev_err(&pdev->dev, "No IRQ resource\n");
+                err = irq;
                 goto fail;
         }