[PATCH 2/2] introduced pcnet_dummy_reset()

[Dmitry Podgorny]

Soft reset (S_RESET) resets value of CSR0 to default. The default
value for CSR0 is 0x0004 (STOP bit is set) [2 p.23]. At first,
assume we in word i/o mode and try to read 0x14. After this try to
read 0x18 if CSR0 hasn't been set to default value.
After S_RESET the controller will be in word i/o mode [1 p.101]. We
need to perform 32bit write access to the i/o location at 0x10 to
switch the controller to dword i/o mode [1 p.104]. Zero is safe
value for this operation [1 p.104].
DWIO bit of BCR18 indicates that the controller is working in dword
mode, if it isn't set something wrong occurred.

[1] Am79C970A
[2] PCnet Family Software Design Considerations
---
 src/pcnet.c |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/src/pcnet.c b/src/pcnet.c
index 480a67f..2372ec3 100644
--- a/src/pcnet.c
+++ b/src/pcnet.c
@@ -182,6 +182,21 @@ static unsigned long pcnet_dummy_bcr_read32(void __iomem *ioaddr,
         return ioread32(ioaddr + PCNET_IO32_BDP) & 0xffff;
 }
 
+/* resets the controller and switches to 32bit mode */
+static int pcnet_dummy_reset(void __iomem *ioaddr)
+{
+	int err = 0;
+	ioread16(ioaddr + PCNET_IO_RESET);
+	if (pcnet_dummy_csr_read16(ioaddr, CSR0) != CSR0_STOP)
+		ioread32(ioaddr + PCNET_IO32_RESET);
+	iowrite32(0, ioaddr + PCNET_IO_RDP);
+	if (!(pcnet_dummy_bcr_read32(ioaddr, BCR18) & BCR18_DWIO)) {
+		printk(KERN_ERR DRV_NAME ": cannot switch controller to 32bit mode\n");
+		err = -ENODEV;
+	}
+	return err;
+}
+
 static int pcnet_dummy_open(struct net_device *ndev)
 {
 	return 0;
@@ -236,7 +251,6 @@ static int __devinit pcnet_dummy_init_netdev(struct pci_dev *pdev,
 #endif /* HAVE_NET_DEVICE_OPS */
 
 	/* registers net_device and returns err */
-	/* TODO: reset the chip at the end */
 
 	return 0;
 }
@@ -272,6 +286,9 @@ static int __devinit pcnet_dummy_init_one(struct pci_dev *pdev,
 		goto out_res;
 	pci_set_drvdata(pdev, ndev);
 
+	if (pcnet_dummy_reset(ioaddr))
+		goto out_res_unmap;
+
 	if (pcnet_dummy_init_netdev(pdev, (unsigned long)ioaddr))
 		goto out_res_unmap;
 
-- 
1.7.5.rc3