gianfar: Add missing graceful reset steps and fixes

gfar_halt() and gfar_start() are responsible for stopping
and starting the DMA and the Rx/Tx hw rings. They implement
the support for the "graceful Rx/Tx stop/start" hw procedure,
and also disable/enable eTSEC's hw interrupts in the process.

The GRS/GTS procedure requires however to have the RQUEUE/TQUEUE
registers cleared first and to wait for a period of time for the
current frame to pass through the interface (around ~10ms for a
jumbo frame). Only then may the GTS and GRS bits from DMACTRL be
set to shut down the DMA, and finally the Tx_EN and Rx_EN bits in
MACCFG1 may be cleared to disable the Tx/Rx blocks.

The same register programming order applies to start the Rx/Tx:
enabling the RQUEUE/TQUEUE *before* clearing the GRS/GTS bits.

This is a HW recommendation in order to avoid a possible
controller "lock up" during graceful reset.

Cleanup the gfar_halt()/start() prototypes, to take priv instead
of ndev as their purpose is to operate on HW. Enabling the
RQUEUE/TQUEUE in the hw_init() is not needed anymore since
that's the job of gfar_start().

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 31 insertions, 30 deletions

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 385de8064371..a2977a8df645 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -138,9 +138,7 @@ int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit);
 static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue);
 static void gfar_process_frame(struct net_device *dev, struct sk_buff *skb,
                                int amount_pull, struct napi_struct *napi);
-void gfar_halt(struct net_device *dev);
-static void gfar_halt_nodisable(struct net_device *dev);
-void gfar_start(struct net_device *dev);
+static void gfar_halt_nodisable(struct gfar_private *priv);
 static void gfar_clear_exact_match(struct net_device *dev);
 static void gfar_set_mac_for_addr(struct net_device *dev, int num,
                                   const u8 *addr);
@@ -1070,10 +1068,6 @@ static void gfar_hw_init(struct gfar_private *priv)
         /* Program the interrupt steering regs, only for MG devices */
         if (priv->num_grps > 1)
                 gfar_write_isrg(priv);
-
-        /* Enable all Rx/Tx queues after MAC reset */
-        gfar_write(&regs->rqueue, priv->rqueue);
-        gfar_write(&regs->tqueue, priv->tqueue);
 }
 
 static void __init gfar_init_addr_hash_table(struct gfar_private *priv)
@@ -1146,7 +1140,7 @@ static int gfar_probe(struct platform_device *ofdev)
         /* Stop the DMA engine now, in case it was running before
          * (The firmware could have used it, and left it running).
          */
-        gfar_halt(dev);
+        gfar_halt(priv);
 
         gfar_hw_init(priv);
 
@@ -1314,7 +1308,7 @@ static int gfar_suspend(struct device *dev)
                 lock_tx_qs(priv);
                 lock_rx_qs(priv);
 
-                gfar_halt_nodisable(ndev);
+                gfar_halt_nodisable(priv);
 
                 /* Disable Tx, and Rx if wake-on-LAN is disabled. */
                 tempval = gfar_read(&regs->maccfg1);
@@ -1378,7 +1372,7 @@ static int gfar_resume(struct device *dev)
         tempval &= ~MACCFG2_MPEN;
         gfar_write(&regs->maccfg2, tempval);
 
-        gfar_start(ndev);
+        gfar_start(priv);
 
         unlock_rx_qs(priv);
         unlock_tx_qs(priv);
@@ -1410,7 +1404,7 @@ static int gfar_restore(struct device *dev)
         init_registers(ndev);
         gfar_set_mac_address(ndev);
         gfar_init_mac(ndev);
-        gfar_start(ndev);
+        gfar_start(priv);
 
         priv->oldlink = 0;
         priv->oldspeed = 0;
@@ -1633,9 +1627,8 @@ static int __gfar_is_rx_idle(struct gfar_private *priv)
 }
 
 /* Halt the receive and transmit queues */
-static void gfar_halt_nodisable(struct net_device *dev)
+static void gfar_halt_nodisable(struct gfar_private *priv)
 {
-        struct gfar_private *priv = netdev_priv(dev);
         struct gfar __iomem *regs = priv->gfargrp[0].regs;
         u32 tempval;
 
@@ -1661,15 +1654,20 @@ static void gfar_halt_nodisable(struct net_device *dev)
 }
 
 /* Halt the receive and transmit queues */
-void gfar_halt(struct net_device *dev)
+void gfar_halt(struct gfar_private *priv)
 {
-        struct gfar_private *priv = netdev_priv(dev);
         struct gfar __iomem *regs = priv->gfargrp[0].regs;
         u32 tempval;
 
-        gfar_halt_nodisable(dev);
+        /* Dissable the Rx/Tx hw queues */
+        gfar_write(&regs->rqueue, 0);
+        gfar_write(&regs->tqueue, 0);
 
-        /* Disable Rx and Tx */
+        mdelay(10);
+
+        gfar_halt_nodisable(priv);
+
+        /* Disable Rx/Tx DMA */
         tempval = gfar_read(&regs->maccfg1);
         tempval &= ~(MACCFG1_RX_EN | MACCFG1_TX_EN);
         gfar_write(&regs->maccfg1, tempval);
@@ -1696,7 +1694,7 @@ void stop_gfar(struct net_device *dev)
         lock_tx_qs(priv);
         lock_rx_qs(priv);
 
-        gfar_halt(dev);
+        gfar_halt(priv);
 
         unlock_rx_qs(priv);
         unlock_tx_qs(priv);
@@ -1801,17 +1799,15 @@ static void free_skb_resources(struct gfar_private *priv)
                           priv->tx_queue[0]->tx_bd_dma_base);
 }
 
-void gfar_start(struct net_device *dev)
+void gfar_start(struct gfar_private *priv)
 {
-        struct gfar_private *priv = netdev_priv(dev);
         struct gfar __iomem *regs = priv->gfargrp[0].regs;
         u32 tempval;
         int i = 0;
 
-        /* Enable Rx and Tx in MACCFG1 */
-        tempval = gfar_read(&regs->maccfg1);
-        tempval |= (MACCFG1_RX_EN | MACCFG1_TX_EN);
-        gfar_write(&regs->maccfg1, tempval);
+        /* Enable Rx/Tx hw queues */
+        gfar_write(&regs->rqueue, priv->rqueue);
+        gfar_write(&regs->tqueue, priv->tqueue);
 
         /* Initialize DMACTRL to have WWR and WOP */
         tempval = gfar_read(&regs->dmactrl);
@@ -1830,9 +1826,14 @@ void gfar_start(struct net_device *dev)
                 gfar_write(&regs->rstat, priv->gfargrp[i].rstat);
         }
 
+        /* Enable Rx/Tx DMA */
+        tempval = gfar_read(&regs->maccfg1);
+        tempval |= (MACCFG1_RX_EN | MACCFG1_TX_EN);
+        gfar_write(&regs->maccfg1, tempval);
+
         gfar_ints_enable(priv);
 
-        dev->trans_start = jiffies; /* prevent tx timeout */
+        priv->ndev->trans_start = jiffies; /* prevent tx timeout */
 }
 
 static void gfar_configure_coalescing(struct gfar_private *priv,
@@ -1956,7 +1957,7 @@ int startup_gfar(struct net_device *ndev)
         }
 
         /* Start the controller */
-        gfar_start(ndev);
+        gfar_start(priv);
 
         phy_start(priv->phydev);
 
diff --git a/drivers/net/ethernet/freescale/gianfar.h b/drivers/net/ethernet/freescale/gianfar.h
index 53e34662b90e..2a59398f8cf0 100644
--- a/drivers/net/ethernet/freescale/gianfar.h
+++ b/drivers/net/ethernet/freescale/gianfar.h
@@ -1205,7 +1205,8 @@ void unlock_tx_qs(struct gfar_private *priv);
 irqreturn_t gfar_receive(int irq, void *dev_id);
 int startup_gfar(struct net_device *dev);
 void stop_gfar(struct net_device *dev);
-void gfar_halt(struct net_device *dev);
+void gfar_halt(struct gfar_private *priv);
+void gfar_start(struct gfar_private *priv);
 void gfar_phy_test(struct mii_bus *bus, struct phy_device *phydev, int enable,
                    u32 regnum, u32 read);
 void gfar_configure_coalescing_all(struct gfar_private *priv);
diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
index 63d234419cc1..69fab72b8a8d 100644
--- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
+++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
@@ -44,7 +44,6 @@
 
 #include "gianfar.h"
 
-extern void gfar_start(struct net_device *dev);
 extern int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue,
                               int rx_work_limit);
 
@@ -504,7 +503,7 @@ static int gfar_sringparam(struct net_device *dev,
                 lock_tx_qs(priv);
                 lock_rx_qs(priv);
 
-                gfar_halt(dev);
+                gfar_halt(priv);
 
                 unlock_rx_qs(priv);
                 unlock_tx_qs(priv);
@@ -627,7 +626,7 @@ int gfar_set_features(struct net_device *dev, netdev_features_t features)
                 lock_tx_qs(priv);
                 lock_rx_qs(priv);
 
-                gfar_halt(dev);
+                gfar_halt(priv);
 
                 unlock_tx_qs(priv);
                 unlock_rx_qs(priv);