Re: [PATCH v3] stmmac: fix check for phydev being open

From: Sergei Shtylyov
Date: Tue Sep 08 2015 - 15:54:40 EST


Hello.

On 09/08/2015 03:46 PM, Alexey Brodkin wrote:

Current check of phydev with IS_ERR(phydev) may make not much sense
because of_phy_connect() returns NULL on failure instead of error value.

Still for checking result of phy_connect() IS_ERR() makes perfect sense.

So let's use combined check IS_ERR_OR_NULL() that covers both cases.

Cc: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: David Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
---

Changes compared to v2:
* Updated commit message with mention of of_phy_connect() instead of
of_phy_attach().
* Return ENODEV in case of of_phy_connect() failure

Changes compared to v1:
* Use IS_ERR_OR_NULL() instead of discrete checks for null and err

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 864b476..e2c9c86 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -837,9 +837,12 @@ static int stmmac_init_phy(struct net_device *dev)
interface);
}

- if (IS_ERR(phydev)) {
+ if (IS_ERR_OR_NULL(phydev)) {
pr_err("%s: Could not attach to PHY\n", dev->name);
- return PTR_ERR(phydev);
+ if (!phydev)
+ return -ENODEV;
+ else
+ return PTR_ERR(phydev);

Don't need *else* after *return* and scripts/checkpatch.pl should have
complained about that.

./scripts/checkpatch.pl 0001-stmmac-fix-check-for-phydev-being-open.patch
total: 0 errors, 0 warnings, 0 checks, 14 lines checked

Hm... I bet I saw such warning from checkpatch.pl recently (it was a false positive though, so maybe the check was removed recently, not sure). Your patch is clean indeed, however my comment is still valid.

-Alexey

MBR, Sergei

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