[PATCH v1 2/6] net/axgbe: toggle PLL settings during rate change

[ssebasti]

From: Selwin Sebastian <selwin.sebast...@amd.com>

For each rate change command submission, the FW has to do a phy
power off sequence internally. For this to happen correctly, the
PLL re-initialization control setting has to be turned off before
sending mailbox commands and re-enabled once the command submission
is complete. Without the PLL control setting, the link up takes
longer time in a fixed phy configuration.

Signed-off-by: Selwin Sebastian <selwin.sebast...@amd.com>
---
 drivers/net/axgbe/axgbe_common.h   |  9 +++++++++
 drivers/net/axgbe/axgbe_phy_impl.c | 22 ++++++++++++++++++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/net/axgbe/axgbe_common.h b/drivers/net/axgbe/axgbe_common.h
index df0aa21a9b..5a7ac35b6a 100644
--- a/drivers/net/axgbe/axgbe_common.h
+++ b/drivers/net/axgbe/axgbe_common.h
@@ -1314,6 +1314,11 @@
 #define MDIO_VEND2_PMA_CDR_CONTROL     0x8056
 #endif
 
+#ifndef MDIO_VEND2_PMA_MISC_CTRL0
+#define MDIO_VEND2_PMA_MISC_CTRL0      0x8090
+#endif
+
+
 #ifndef MDIO_CTRL1_SPEED1G
 #define MDIO_CTRL1_SPEED1G             (MDIO_CTRL1_SPEED10G & ~BMCR_SPEED100)
 #endif
@@ -1392,6 +1397,10 @@ static inline uint32_t high32_value(uint64_t addr)
        return (addr >> 32) & 0x0ffffffff;
 }
 
+#define XGBE_PMA_PLL_CTRL_MASK         BIT(15)
+#define XGBE_PMA_PLL_CTRL_SET          BIT(15)
+#define XGBE_PMA_PLL_CTRL_CLEAR                0x0000
+
 /*END*/
 
 /* Bit setting and getting macros
diff --git a/drivers/net/axgbe/axgbe_phy_impl.c 
b/drivers/net/axgbe/axgbe_phy_impl.c
index 02236ec192..dc9489f0aa 100644
--- a/drivers/net/axgbe/axgbe_phy_impl.c
+++ b/drivers/net/axgbe/axgbe_phy_impl.c
@@ -1196,8 +1196,22 @@ static void axgbe_phy_set_redrv_mode(struct axgbe_port 
*pdata)
        axgbe_phy_put_comm_ownership(pdata);
 }
 
+static void axgbe_phy_pll_ctrl(struct axgbe_port *pdata, bool enable)
+{
+       XMDIO_WRITE_BITS(pdata, MDIO_MMD_PMAPMD, MDIO_VEND2_PMA_MISC_CTRL0,
+                       XGBE_PMA_PLL_CTRL_MASK,
+                       enable ? XGBE_PMA_PLL_CTRL_SET
+                       : XGBE_PMA_PLL_CTRL_CLEAR);
+
+       /* Wait for command to complete */
+       rte_delay_us(150);
+}
+
 static void axgbe_phy_start_ratechange(struct axgbe_port *pdata)
 {
+       /* Clear the PLL so that it helps in power down sequence */
+       axgbe_phy_pll_ctrl(pdata, false);
+
        /* Log if a previous command did not complete */
        if (XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS))
                PMD_DRV_LOG(NOTICE, "firmware mailbox not ready for command\n");
@@ -1213,10 +1227,14 @@ static void axgbe_phy_complete_ratechange(struct 
axgbe_port *pdata)
        wait = AXGBE_RATECHANGE_COUNT;
        while (wait--) {
                if (!XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS))
-                       return;
-
+                       goto reenable_pll;
                rte_delay_us(1500);
        }
+
+reenable_pll:
+        /* Re-enable the PLL control */
+       axgbe_phy_pll_ctrl(pdata, true);
+
        PMD_DRV_LOG(NOTICE, "firmware mailbox command did not complete\n");
 }
 
-- 
2.25.1