TULIP: Natsemi dp83840a PHY fix

Fix a problem with Tulip 21142 HP branded PCI cards (PN#: B5509-66001),
which feature a NatSemi DP83840A PHY.

Without that patch, it is impossible to properly initialize the card's PHY,
and it's thus impossible to monitor/configure it.

[VAL: I'm happy with the 1.5 ms max delay; it doesn't seem excessive.]

Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Valerie Henson <val_henson@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/net/tulip/media.c b/drivers/net/tulip/media.c
index 1594160a0f62..b56256636543 100644
--- a/drivers/net/tulip/media.c
+++ b/drivers/net/tulip/media.c
@@ -263,11 +263,27 @@ void tulip_select_media(struct net_device *dev, int startup)
                                 u16 *reset_sequence = &((u16*)(p+3))[init_length];
                                 int reset_length = p[2 + init_length*2];
                                 misc_info = reset_sequence + reset_length;
-                                if (startup)
+                                if (startup) {
+                                        int timeout = 10;       /* max 1 ms */
                                         for (i = 0; i < reset_length; i++)
                                                 iowrite32(get_u16(&reset_sequence[i]) << 16, ioaddr + CSR15);
+
+                                        /* flush posted writes */
+                                        ioread32(ioaddr + CSR15);
+
+                                        /* Sect 3.10.3 in DP83840A.pdf (p39) */
+                                        udelay(500);
+
+                                        /* Section 4.2 in DP83840A.pdf (p43) */
+                                        /* and IEEE 802.3 "22.2.4.1.1 Reset" */
+                                        while (timeout-- &&
+                                                (tulip_mdio_read (dev, phy_num, MII_BMCR) & BMCR_RESET))
+                                                udelay(100);
+                                }
                                 for (i = 0; i < init_length; i++)
                                         iowrite32(get_u16(&init_sequence[i]) << 16, ioaddr + CSR15);
+
+                                ioread32(ioaddr + CSR15);       /* flush posted writes */
                         } else {
                                 u8 *init_sequence = p + 2;
                                 u8 *reset_sequence = p + 3 + init_length;