ks8851: Fix missing mutex_lock/unlock

Move the ks8851_rdreg16 call above the call to request_irq and cache
the result for subsequent repeated use.  A spurious interrupt may
otherwise cause a crash.  Thanks to Stephen Boyd, Flavio Leitner, and
Ben Hutchings for feedback.

Signed-off-by: Matt Renzelmann <mjr@cs.wisc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index c722aa607d074796985b9028c5c91752459aad8e..e5dc0757f077e12287606c9191d3d2617fb0bd3f 100644 (file)
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -1418,6 +1418,7 @@ static int __devinit ks8851_probe(struct spi_device *spi)
        struct net_device *ndev;
        struct ks8851_net *ks;
        int ret;
+       unsigned cider;
 
        ndev = alloc_etherdev(sizeof(struct ks8851_net));
        if (!ndev)
@@ -1484,8 +1485,8 @@ static int __devinit ks8851_probe(struct spi_device *spi)
        ks8851_soft_reset(ks, GRR_GSR);
 
        /* simple check for a valid chip being connected to the bus */
-
-       if ((ks8851_rdreg16(ks, KS_CIDER) & ~CIDER_REV_MASK) != CIDER_ID) {
+       cider = ks8851_rdreg16(ks, KS_CIDER);
+       if ((cider & ~CIDER_REV_MASK) != CIDER_ID) {
                dev_err(&spi->dev, "failed to read device ID\n");
                ret = -ENODEV;
                goto err_id;
@@ -1516,8 +1517,7 @@ static int __devinit ks8851_probe(struct spi_device *spi)
        }
 
        netdev_info(ndev, "revision %d, MAC %pM, IRQ %d, %s EEPROM\n",
-                   CIDER_REV_GET(ks8851_rdreg16(ks, KS_CIDER)),
-                   ndev->dev_addr, ndev->irq,
+                   CIDER_REV_GET(cider), ndev->dev_addr, ndev->irq,
                    ks->rc_ccr & CCR_EEPROM ? "has" : "no");
 
        return 0;