can: rcar_can: fix IRQ check

commit 5e63e6baa159fa8c787cf783dbf3d77fbea97331 upstream.

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>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
index 7deb80d..93017c0 100644 (file)
--- 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;
        }