[PATCH net-next 10/13] net: mvpp2: reset the XPCS while reconfiguring the serdes lanes

[Antoine Tenart]

The documentation advises to set the XPCS in reset while reconfiguring
the serdes lanes. This seems to be a good thing to do, but the PPv2
driver wasn't doing it. This patch fixes it.

Signed-off-by: Antoine Tenart <antoine.ten...@bootlin.com>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2.h      | 1 +
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h 
b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index 21ddcac1ceea..7380bddc53b8 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -481,6 +481,7 @@
 /* XPCS registers. PPv2.2 only */
 #define MVPP22_XPCS_BASE(port)                 (0x7400 + (port) * 0x1000)
 #define MVPP22_XPCS_CFG0                       0x0
+#define     MVPP22_XPCS_CFG0_RESET_DIS         BIT(0)
 #define     MVPP22_XPCS_CFG0_PCS_MODE(n)       ((n) << 3)
 #define     MVPP22_XPCS_CFG0_ACTIVE_LANE(n)    ((n) << 5)
 
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c 
b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 4a18f8e54c90..5d05306e79a8 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -1016,13 +1016,19 @@ static void mvpp22_gop_init_10gkr(struct mvpp2_port 
*port)
        void __iomem *xpcs = priv->iface_base + MVPP22_XPCS_BASE(port->gop_id);
        u32 val;
 
-       /* XPCS */
+       /* XPCS : Reset the XPCS when reconfiguring the lanes */
+       val = readl(xpcs + MVPP22_XPCS_CFG0);
+       writel(val & ~MVPP22_XPCS_CFG0_RESET_DIS, xpcs + MVPP22_XPCS_CFG0);
+
        val = readl(xpcs + MVPP22_XPCS_CFG0);
        val &= ~(MVPP22_XPCS_CFG0_PCS_MODE(0x3) |
                 MVPP22_XPCS_CFG0_ACTIVE_LANE(0x3));
        val |= MVPP22_XPCS_CFG0_ACTIVE_LANE(2);
        writel(val, xpcs + MVPP22_XPCS_CFG0);
 
+       val = readl(xpcs + MVPP22_XPCS_CFG0);
+       writel(val | MVPP22_XPCS_CFG0_RESET_DIS, xpcs + MVPP22_XPCS_CFG0);
+
        /* MPCS */
        val = readl(mpcs + MVPP22_MPCS_CTRL);
        val &= ~MVPP22_MPCS_CTRL_FWD_ERR_CONN;
-- 
2.20.1