[PATCH] net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats

[PATCH] net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats

[Nathan Chancellor]

Clang warns:

drivers/net/dsa/sja1105/sja1105_ethtool.c:316:39: warning: suggest
braces around initialization of subobject [-Wmissing-braces]
        struct sja1105_port_status status = {0};
                                             ^
                                             {}
1 warning generated.

One way to fix these warnings is to add additional braces like Clang
suggests; however, there has been a bit of push back from some
maintainers[1][2], who just prefer memset as it is unambiguous, doesn't
depend on a particular compiler version[3], and properly initializes all
subobjects. Do that here so there are no more warnings.

[1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@amd.com/
[2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@davemloft.net/
[3]: https://lore.kernel.org/lkml/20181116150432.2408a075@redhat.com/

Fixes: 52c34e6e125c ("net: dsa: sja1105: Add support for ethtool port counters")
Link: https://github.com/ClangBuiltLinux/linux/issues/471
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/net/dsa/sja1105/sja1105_ethtool.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/sja1105/sja1105_ethtool.c b/drivers/net/dsa/sja1105/sja1105_ethtool.c
index 46d22be31309..ab581a28cd41 100644
--- a/drivers/net/dsa/sja1105/sja1105_ethtool.c
+++ b/drivers/net/dsa/sja1105/sja1105_ethtool.c
@@ -313,9 +313,11 @@ static char sja1105pqrs_extra_port_stats[][ETH_GSTRING_LEN] = {
 void sja1105_get_ethtool_stats(struct dsa_switch *ds, int port, u64 *data)
 {
 	struct sja1105_private *priv = ds->priv;
-	struct sja1105_port_status status = {0};
+	struct sja1105_port_status status;
 	int rc, i, k = 0;
 
+	memset(&status, 0, sizeof(status));
+
 	rc = sja1105_port_status_get(priv, &status, port);
 	if (rc < 0) {
 		dev_err(ds->dev, "Failed to read port %d counters: %d\n",
-- 
2.21.0

Re: [PATCH] net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats

[Vladimir Oltean]

On Mon, 6 May 2019 at 23:25, Nathan Chancellor <natechancellor@gmail.com> wrote:
>
> Clang warns:
>
> drivers/net/dsa/sja1105/sja1105_ethtool.c:316:39: warning: suggest
> braces around initialization of subobject [-Wmissing-braces]
>         struct sja1105_port_status status = {0};
>                                              ^
>                                              {}
> 1 warning generated.
>
> One way to fix these warnings is to add additional braces like Clang
> suggests; however, there has been a bit of push back from some
> maintainers[1][2], who just prefer memset as it is unambiguous, doesn't
> depend on a particular compiler version[3], and properly initializes all
> subobjects. Do that here so there are no more warnings.
>
> [1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@amd.com/
> [2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@davemloft.net/
> [3]: https://lore.kernel.org/lkml/20181116150432.2408a075@redhat.com/
>
> Fixes: 52c34e6e125c ("net: dsa: sja1105: Add support for ethtool port counters")
> Link: https://github.com/ClangBuiltLinux/linux/issues/471
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/net/dsa/sja1105/sja1105_ethtool.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/dsa/sja1105/sja1105_ethtool.c b/drivers/net/dsa/sja1105/sja1105_ethtool.c
> index 46d22be31309..ab581a28cd41 100644
> --- a/drivers/net/dsa/sja1105/sja1105_ethtool.c
> +++ b/drivers/net/dsa/sja1105/sja1105_ethtool.c
> @@ -313,9 +313,11 @@ static char sja1105pqrs_extra_port_stats[][ETH_GSTRING_LEN] = {
>  void sja1105_get_ethtool_stats(struct dsa_switch *ds, int port, u64 *data)
>  {
>         struct sja1105_private *priv = ds->priv;
> -       struct sja1105_port_status status = {0};
> +       struct sja1105_port_status status;
>         int rc, i, k = 0;
>
> +       memset(&status, 0, sizeof(status));
> +
>         rc = sja1105_port_status_get(priv, &status, port);
>         if (rc < 0) {
>                 dev_err(ds->dev, "Failed to read port %d counters: %d\n",
> --
> 2.21.0
>

Acked-by: Vladimir Oltean <olteanv@gmail.com>

Thanks Nathan, compound literals got me this time.
-Vladimir

Re: [PATCH] net: dsa: sja1105: Fix status initialization in sja1105_get_ethtool_stats

[David Miller]

From: Nathan Chancellor <natechancellor@gmail.com>
Date: Mon,  6 May 2019 13:24:47 -0700

> Clang warns:
> 
> drivers/net/dsa/sja1105/sja1105_ethtool.c:316:39: warning: suggest
> braces around initialization of subobject [-Wmissing-braces]
>         struct sja1105_port_status status = {0};
>                                              ^
>                                              {}
> 1 warning generated.
> 
> One way to fix these warnings is to add additional braces like Clang
> suggests; however, there has been a bit of push back from some
> maintainers[1][2], who just prefer memset as it is unambiguous, doesn't
> depend on a particular compiler version[3], and properly initializes all
> subobjects. Do that here so there are no more warnings.
> 
> [1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@amd.com/
> [2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@davemloft.net/
> [3]: https://lore.kernel.org/lkml/20181116150432.2408a075@redhat.com/
> 
> Fixes: 52c34e6e125c ("net: dsa: sja1105: Add support for ethtool port counters")
> Link: https://github.com/ClangBuiltLinux/linux/issues/471
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Applied to net-next.