net: dsa: yt921x: Fix MIB attribute table

[PATCH net-next] net: dsa: yt921x: Fix MIB attribute table

Posted by David Yang 1 week, 6 days ago

There are holes in the MIB field I didn't notice, leading to wrong
statistics after stress tests.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/dsa/yt921x.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 944988e29127..97fc6085f4d0 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -56,13 +56,13 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
 
 	MIB_DESC(1, 0x30, NULL),	/* RxPktSz1024To1518 */
 	MIB_DESC(1, 0x34, NULL),	/* RxPktSz1519ToMax */
-	MIB_DESC(2, 0x38, NULL),	/* RxGoodBytes */
-	/* 0x3c */
+	/* 0x38 unused */
+	MIB_DESC(2, 0x3c, NULL),	/* RxGoodBytes */
 
-	MIB_DESC(2, 0x40, "RxBadBytes"),
-	/* 0x44 */
-	MIB_DESC(2, 0x48, NULL),	/* RxOverSzErr */
-	/* 0x4c */
+	/* 0x40 */
+	MIB_DESC(2, 0x44, "RxBadBytes"),
+	/* 0x48 */
+	MIB_DESC(1, 0x4c, NULL),	/* RxOverSzErr */
 
 	MIB_DESC(1, 0x50, NULL),	/* RxDropped */
 	MIB_DESC(1, 0x54, NULL),	/* TxBroadcast */
@@ -79,10 +79,10 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
 	MIB_DESC(1, 0x78, NULL),	/* TxPktSz1024To1518 */
 	MIB_DESC(1, 0x7c, NULL),	/* TxPktSz1519ToMax */
 
-	MIB_DESC(2, 0x80, NULL),	/* TxGoodBytes */
-	/* 0x84 */
-	MIB_DESC(2, 0x88, NULL),	/* TxCollision */
-	/* 0x8c */
+	/* 0x80 unused */
+	MIB_DESC(2, 0x84, NULL),	/* TxGoodBytes */
+	/* 0x88 */
+	MIB_DESC(1, 0x8c, NULL),	/* TxCollision */
 
 	MIB_DESC(1, 0x90, NULL),	/* TxExcessiveCollistion */
 	MIB_DESC(1, 0x94, NULL),	/* TxMultipleCollision */
@@ -705,7 +705,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
 			res = yt921x_reg_read(priv, reg + 4, &val1);
 			if (res)
 				break;
-			val = ((u64)val0 << 32) | val1;
+			val = ((u64)val1 << 32) | val0;
 		}
 
 		WRITE_ONCE(*valp, val);
-- 
2.51.0

Re: [PATCH net-next] net: dsa: yt921x: Fix MIB attribute table

Posted by Andrew Lunn 1 week, 6 days ago

On Tue, Nov 18, 2025 at 05:12:33PM +0800, David Yang wrote:
> There are holes in the MIB field I didn't notice, leading to wrong
> statistics after stress tests.
> 
> Signed-off-by: David Yang <mmyangfl@gmail.com>
> ---
>  drivers/net/dsa/yt921x.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
> index 944988e29127..97fc6085f4d0 100644
> --- a/drivers/net/dsa/yt921x.c
> +++ b/drivers/net/dsa/yt921x.c
> @@ -56,13 +56,13 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
>  
>  	MIB_DESC(1, 0x30, NULL),	/* RxPktSz1024To1518 */
>  	MIB_DESC(1, 0x34, NULL),	/* RxPktSz1519ToMax */
> -	MIB_DESC(2, 0x38, NULL),	/* RxGoodBytes */
> -	/* 0x3c */
> +	/* 0x38 unused */
> +	MIB_DESC(2, 0x3c, NULL),	/* RxGoodBytes */

How is this described in the datasheet? Maybe add #defines for each
location? At could mean you don't need the comment, since the #define
documents what it is.

> @@ -705,7 +705,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
>  			res = yt921x_reg_read(priv, reg + 4, &val1);
>  			if (res)
>  				break;
> -			val = ((u64)val0 << 32) | val1;
> +			val = ((u64)val1 << 32) | val0;

And that is a different thing, has nothing to do with holes. This
should be mentioned in the commit message.

    Andrew

---
pw-bot: cr

Re: [PATCH net-next] net: dsa: yt921x: Fix MIB attribute table

Posted by Maxime Chevallier 1 week, 6 days ago

Hi David,

On 18/11/2025 10:12, David Yang wrote:
> There are holes in the MIB field I didn't notice, leading to wrong
> statistics after stress tests.
> 
> Signed-off-by: David Yang <mmyangfl@gmail.com>

Even if this is fixing a patch that's still in net-next, you may want to
add a fixes tag, as this is a bugfix :/

Maxime

> ---
>  drivers/net/dsa/yt921x.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
> index 944988e29127..97fc6085f4d0 100644
> --- a/drivers/net/dsa/yt921x.c
> +++ b/drivers/net/dsa/yt921x.c
> @@ -56,13 +56,13 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
>  
>  	MIB_DESC(1, 0x30, NULL),	/* RxPktSz1024To1518 */
>  	MIB_DESC(1, 0x34, NULL),	/* RxPktSz1519ToMax */
> -	MIB_DESC(2, 0x38, NULL),	/* RxGoodBytes */
> -	/* 0x3c */
> +	/* 0x38 unused */
> +	MIB_DESC(2, 0x3c, NULL),	/* RxGoodBytes */
>  
> -	MIB_DESC(2, 0x40, "RxBadBytes"),
> -	/* 0x44 */
> -	MIB_DESC(2, 0x48, NULL),	/* RxOverSzErr */
> -	/* 0x4c */
> +	/* 0x40 */
> +	MIB_DESC(2, 0x44, "RxBadBytes"),
> +	/* 0x48 */
> +	MIB_DESC(1, 0x4c, NULL),	/* RxOverSzErr */
>  
>  	MIB_DESC(1, 0x50, NULL),	/* RxDropped */
>  	MIB_DESC(1, 0x54, NULL),	/* TxBroadcast */
> @@ -79,10 +79,10 @@ static const struct yt921x_mib_desc yt921x_mib_descs[] = {
>  	MIB_DESC(1, 0x78, NULL),	/* TxPktSz1024To1518 */
>  	MIB_DESC(1, 0x7c, NULL),	/* TxPktSz1519ToMax */
>  
> -	MIB_DESC(2, 0x80, NULL),	/* TxGoodBytes */
> -	/* 0x84 */
> -	MIB_DESC(2, 0x88, NULL),	/* TxCollision */
> -	/* 0x8c */
> +	/* 0x80 unused */
> +	MIB_DESC(2, 0x84, NULL),	/* TxGoodBytes */
> +	/* 0x88 */
> +	MIB_DESC(1, 0x8c, NULL),	/* TxCollision */
>  
>  	MIB_DESC(1, 0x90, NULL),	/* TxExcessiveCollistion */
>  	MIB_DESC(1, 0x94, NULL),	/* TxMultipleCollision */
> @@ -705,7 +705,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
>  			res = yt921x_reg_read(priv, reg + 4, &val1);
>  			if (res)
>  				break;
> -			val = ((u64)val0 << 32) | val1;
> +			val = ((u64)val1 << 32) | val0;
>  		}
>  
>  		WRITE_ONCE(*valp, val);