net/sonic: Quiesce SONIC before re-initializing descriptor memory

commit 3f4b7e6a2be982fd8820a2b54d46dd9c351db899 upstream.

Make sure the SONIC's DMA engine is idle before altering the transmit
and receive descriptors. Add a helper for this as it will be needed
again.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/natsemi/sonic.c b/drivers/net/ethernet/natsemi/sonic.c
index 26848ac..42a6b87 100644 (file)
--- a/drivers/net/ethernet/natsemi/sonic.c
+++ b/drivers/net/ethernet/natsemi/sonic.c
@@ -116,6 +116,24 @@ static int sonic_open(struct net_device *dev)
        return 0;
 }
 
+/* Wait for the SONIC to become idle. */
+static void sonic_quiesce(struct net_device *dev, u16 mask)
+{
+       struct sonic_local * __maybe_unused lp = netdev_priv(dev);
+       int i;
+       u16 bits;
+
+       for (i = 0; i < 1000; ++i) {
+               bits = SONIC_READ(SONIC_CMD) & mask;
+               if (!bits)
+                       return;
+               if (irqs_disabled() || in_interrupt())
+                       udelay(20);
+               else
+                       usleep_range(100, 200);
+       }
+       WARN_ONCE(1, "command deadline expired! 0x%04x\n", bits);
+}
 
 /*
  * Close the SONIC device
@@ -132,6 +150,9 @@ static int sonic_close(struct net_device *dev)
        /*
         * stop the SONIC, disable interrupts
         */
+       SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+       sonic_quiesce(dev, SONIC_CR_ALL);
+
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -171,6 +192,9 @@ static void sonic_tx_timeout(struct net_device *dev)
         * put the Sonic into software-reset mode and
         * disable all interrupts before releasing DMA buffers
         */
+       SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+       sonic_quiesce(dev, SONIC_CR_ALL);
+
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -658,6 +682,7 @@ static int sonic_init(struct net_device *dev)
         */
        SONIC_WRITE(SONIC_CMD, 0);
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+       sonic_quiesce(dev, SONIC_CR_ALL);
 
        /*
         * initialize the receive resource area

diff --git a/drivers/net/ethernet/natsemi/sonic.h b/drivers/net/ethernet/natsemi/sonic.h
index cc2f7b4..1df6d2f 100644 (file)
--- a/drivers/net/ethernet/natsemi/sonic.h
+++ b/drivers/net/ethernet/natsemi/sonic.h
@@ -110,6 +110,9 @@
 #define SONIC_CR_TXP            0x0002
 #define SONIC_CR_HTX            0x0001
 
+#define SONIC_CR_ALL (SONIC_CR_LCAM | SONIC_CR_RRRA | \
+                     SONIC_CR_RXEN | SONIC_CR_TXP)
+
 /*
  * SONIC data configuration bits
  */