2021-04-22 07:50:10

by Ismail, Mohammad Athari

Subject: [PATCH net-next] net: pcs: Enable pre-emption packet for 10/100Mbps

From: Mohammad Athari Bin Ismail <[email protected]>

Set VR_MII_DIG_CTRL1 bit-6(PRE_EMP) to enable pre-emption packet for
10/100Mbps by default. This setting doesn`t impact pre-emption
capability for other speeds.

Signed-off-by: Mohammad Athari Bin Ismail <[email protected]>
---
drivers/net/pcs/pcs-xpcs.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 944ba105cac1..2dbc1d46821e 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -66,6 +66,7 @@

/* VR_MII_DIG_CTRL1 */
#define DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW BIT(9)
+#define DW_VR_MII_DIG_CTRL1_PRE_EMP BIT(6)

/* VR_MII_AN_CTRL */
#define DW_VR_MII_AN_CTRL_TX_CONFIG_SHIFT 3
@@ -666,6 +667,10 @@ static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
* PHY about the link state change after C28 AN is completed
* between PHY and Link Partner. There is also no need to
* trigger AN restart for MAC-side SGMII.
+ *
+ * For pre-emption, the setting is :-
+ * 1) VR_MII_DIG_CTRL1 Bit(6) [PRE_EMP] = 1b (Enable pre-emption packet
+ * for 10/100Mbps)
*/
ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_CTRL);
if (ret < 0)
@@ -686,7 +691,7 @@ static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
if (ret < 0)
return ret;

- ret |= DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW;
+ ret |= (DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW | DW_VR_MII_DIG_CTRL1_PRE_EMP);

return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL1, ret);
}
--
2.17.1

2021-04-22 08:17:36

by Leon Romanovsky

Subject: Re: [PATCH net-next] net: pcs: Enable pre-emption packet for 10/100Mbps

On Thu, Apr 22, 2021 at 03:48:51PM +0800, [email protected] wrote:
> From: Mohammad Athari Bin Ismail <[email protected]>
>
> Set VR_MII_DIG_CTRL1 bit-6(PRE_EMP) to enable pre-emption packet for
> 10/100Mbps by default. This setting doesn`t impact pre-emption
> capability for other speeds.
>
> Signed-off-by: Mohammad Athari Bin Ismail <[email protected]>
> ---
> drivers/net/pcs/pcs-xpcs.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
> index 944ba105cac1..2dbc1d46821e 100644
> --- a/drivers/net/pcs/pcs-xpcs.c
> +++ b/drivers/net/pcs/pcs-xpcs.c
> @@ -66,6 +66,7 @@
>
> /* VR_MII_DIG_CTRL1 */
> #define DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW BIT(9)
> +#define DW_VR_MII_DIG_CTRL1_PRE_EMP BIT(6)
>
> /* VR_MII_AN_CTRL */
> #define DW_VR_MII_AN_CTRL_TX_CONFIG_SHIFT 3
> @@ -666,6 +667,10 @@ static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
> * PHY about the link state change after C28 AN is completed
> * between PHY and Link Partner. There is also no need to
> * trigger AN restart for MAC-side SGMII.
> + *
> + * For pre-emption, the setting is :-
> + * 1) VR_MII_DIG_CTRL1 Bit(6) [PRE_EMP] = 1b (Enable pre-emption packet
> + * for 10/100Mbps)
> */
> ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_CTRL);
> if (ret < 0)
> @@ -686,7 +691,7 @@ static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
> if (ret < 0)
> return ret;
>
> - ret |= DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW;
> + ret |= (DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW | DW_VR_MII_DIG_CTRL1_PRE_EMP);

() are useless here.

Thanks

>
> return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL1, ret);
> }
> --
> 2.17.1
>