diff options
| author | Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com> | 2024-06-21 17:43:21 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-06-23 12:06:58 +0300 |
| commit | d963c95bc9840d070a788c35e41b715a648717f7 (patch) | |
| tree | ba12e572aae4271f726d2f7fb424eb4120f42a33 /drivers/net | |
| parent | 54a4e5c16382e871c01dd82b47e930fdce30406b (diff) | |
| download | linux-d963c95bc9840d070a788c35e41b715a648717f7.tar.xz | |
net: dsa: microchip: use collision based back pressure mode
Errata DS80000758 states that carrier sense back pressure mode can cause
link down issues in 100BASE-TX half duplex mode. The datasheet also
recommends to always use the collision based back pressure mode.
Fixes: b987e98e50ab ("dsa: add DSA switch driver for Microchip KSZ9477")
Signed-off-by: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com>
Reviewed-by: Woojung Huh <Woojung.huh@microchip.com>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/dsa/microchip/ksz9477.c | 4 | ||||
| -rw-r--r-- | drivers/net/dsa/microchip/ksz9477_reg.h | 1 |
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c index 2231128eef8b..cbaca4140cda 100644 --- a/drivers/net/dsa/microchip/ksz9477.c +++ b/drivers/net/dsa/microchip/ksz9477.c @@ -1297,6 +1297,10 @@ int ksz9477_setup(struct dsa_switch *ds) /* Enable REG_SW_MTU__2 reg by setting SW_JUMBO_PACKET */ ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_JUMBO_PACKET, true); + /* Use collision based back pressure mode. */ + ksz_cfg(dev, REG_SW_MAC_CTRL_1, SW_BACK_PRESSURE, + SW_BACK_PRESSURE_COLLISION); + /* Now we can configure default MTU value */ ret = regmap_update_bits(ksz_regmap_16(dev), REG_SW_MTU__2, REG_SW_MTU_MASK, VLAN_ETH_FRAME_LEN + ETH_FCS_LEN); diff --git a/drivers/net/dsa/microchip/ksz9477_reg.h b/drivers/net/dsa/microchip/ksz9477_reg.h index f3a205ee483f..fb124be8edd3 100644 --- a/drivers/net/dsa/microchip/ksz9477_reg.h +++ b/drivers/net/dsa/microchip/ksz9477_reg.h @@ -247,6 +247,7 @@ #define REG_SW_MAC_CTRL_1 0x0331 #define SW_BACK_PRESSURE BIT(5) +#define SW_BACK_PRESSURE_COLLISION 0 #define FAIR_FLOW_CTRL BIT(4) #define NO_EXC_COLLISION_DROP BIT(3) #define SW_JUMBO_PACKET BIT(2) |