Re: [PATCH 03/10] net: ezchip: nps_enet: Fix platform_get_irq's error checking

From: Russell King - ARM Linux <linux@armlinux.org.uk>
Date: Mon, 4 Dec 2017 16:24:47 +0000

On Mon, Dec 04, 2017 at 11:20:49AM -0500, David Miller wrote:

quoted

From: Arvind Yadav <redacted>
Date: Sun,  3 Dec 2017 00:56:15 +0530

quoted

The platform_get_irq() function returns negative if an error occurs.
zero or positive number on success. platform_get_irq() error checking
for zero is not correct. And remove unnecessary check for free_netdev().

Signed-off-by: Arvind Yadav <redacted>
---
 drivers/net/ethernet/ezchip/nps_enet.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ezchip/nps_enet.c b/drivers/net/ethernet/ezchip/nps_enet.c
index 659f1ad..82dc6d0 100644
--- a/drivers/net/ethernet/ezchip/nps_enet.c
+++ b/drivers/net/ethernet/ezchip/nps_enet.c

@@ -623,9 +623,9 @@ static s32 nps_enet_probe(struct platform_device *pdev)
 
 	/* Get IRQ number */
 	priv->irq = platform_get_irq(pdev, 0);
-	if (!priv->irq) {
+	if (priv->irq <= 0) {
 		dev_err(dev, "failed to retrieve <irq Rx-Tx> value from device tree\n");
-		err = -ENODEV;
+		err = priv->irq ? priv->irq : -ENODEV;

If platform_get_irq() returns "zero or positive number on success" then this
test is wrong and should be "if (priv->irq < 0)"

Also, this series is a mix of different kinds of changes.

Please separate out the platform IRQ error checking and just submit exactly
those changes as a patch series.

The other bug fixes should be submitted outside of those changes since they
are unrelated.

The issue of whether IRQ 0 is valid or not has been covered several times
by Linus, and the result is that it is deemed by Linus that IRQ 0 is not
a valid interrupt.

Then either platform_get_irq() as defined or this commit message (or both)
are wrong.