[PATCH net] net: systemport: Fix CRC forwarding check for SYSTEMPORT Lite

[PATCH net] net: systemport: Fix CRC forwarding check for SYSTEMPORT Lite

[Florian Fainelli]

SYSTEMPORT Lite reversed the logic compared to SYSTEMPORT, the
GIB_FCS_STRIP bit is set when the Ethernet FCS is stripped, and that bit
is not set by default. Fix the logic such that we properly check whether
that bit is set or not and we don't forward an extra 4 bytes to the
network stack.

Fixes: 44a4524c54af ("net: systemport: Add support for SYSTEMPORT Lite")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 4 ++--
 drivers/net/ethernet/broadcom/bcmsysport.h | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index d5fca2e5a9bc..a1f60f89e059 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -1946,8 +1946,8 @@ static int bcm_sysport_open(struct net_device *dev)
 	if (!priv->is_lite)
 		priv->crc_fwd = !!(umac_readl(priv, UMAC_CMD) & CMD_CRC_FWD);
 	else
-		priv->crc_fwd = !!(gib_readl(priv, GIB_CONTROL) &
-				   GIB_FCS_STRIP);
+		priv->crc_fwd = !((gib_readl(priv, GIB_CONTROL) &
+				  GIB_FCS_STRIP) >> GIB_FCS_STRIP_SHIFT);
 
 	phydev = of_phy_connect(dev, priv->phy_dn, bcm_sysport_adj_link,
 				0, priv->phy_interface);
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.h b/drivers/net/ethernet/broadcom/bcmsysport.h
index d6e5d0cbf3a3..cf440b91fd04 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.h
+++ b/drivers/net/ethernet/broadcom/bcmsysport.h
@@ -278,7 +278,8 @@ struct bcm_rsb {
 #define  GIB_GTX_CLK_EXT_CLK		(0 << GIB_GTX_CLK_SEL_SHIFT)
 #define  GIB_GTX_CLK_125MHZ		(1 << GIB_GTX_CLK_SEL_SHIFT)
 #define  GIB_GTX_CLK_250MHZ		(2 << GIB_GTX_CLK_SEL_SHIFT)
-#define  GIB_FCS_STRIP			(1 << 6)
+#define  GIB_FCS_STRIP_SHIFT		6
+#define  GIB_FCS_STRIP			(1 << GIB_FCS_STRIP_SHIFT)
 #define  GIB_LCL_LOOP_EN		(1 << 7)
 #define  GIB_LCL_LOOP_TXEN		(1 << 8)
 #define  GIB_RMT_LOOP_EN		(1 << 9)
-- 
2.14.1

Re: [PATCH net] net: systemport: Fix CRC forwarding check for SYSTEMPORT Lite

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Wed, 11 Jul 2018 02:47:58 -0700

> SYSTEMPORT Lite reversed the logic compared to SYSTEMPORT, the
> GIB_FCS_STRIP bit is set when the Ethernet FCS is stripped, and that bit
> is not set by default. Fix the logic such that we properly check whether
> that bit is set or not and we don't forward an extra 4 bytes to the
> network stack.
> 
> Fixes: 44a4524c54af ("net: systemport: Add support for SYSTEMPORT Lite")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Applied.