From: Neil Horman <nhorman@redhat.com>
Date: Wed, 27 May 2009 15:42:21 -0400
Subject: [net] sky2: fix eeprom reads
Message-id: 20090527194221.GZ19071@hmsreliant.think-freely.org
O-Subject: Re: [RHEL 5.4 PATCH] sky2: Fix eeprom reads (bz 501050)
Bugzilla: 501050
RH-Acked-by: Andy Gospodarek <gospo@redhat.com>

On Wed, May 27, 2009 at 12:29:01PM -0400, Andy Gospodarek wrote:
> On Wed, May 27, 2009 at 11:47:53AM -0400, Neil Horman wrote:
> > Hey all-
> > 	This is a backport of upstream commit
> > 1413235c14301c4bd27aabf408e4336719b6f505 and supporting bits from
> > e4c2abe29e1ec5d68908848ffa77b39f61a83f7c.  They fix sky2s eeprom reading code,
> > As it currently stands, the sky2 eeprom reading code can spin forever, and is
> > able to write half words, which is both unnneeded and unsafe.  In the sky2 card
> > this mentioned in this bz, it seems to cause an internal hw error which results
> > in no frames getting sent or received.  This patch fixes that and will allow the
> > system in question to continue their hwcert process.
> >
> > Neil

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index b8515b8..9a35837 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -3758,63 +3758,27 @@ static int sky2_get_eeprom_len(struct net_device *dev)
 	return 1 << ( ((reg2 & PCI_VPD_ROM_SZ) >> 14) + 8);
 }
 
-static int sky2_vpd_wait(const struct sky2_hw *hw, int cap, u16 busy)
+static u32 sky2_vpd_read(struct sky2_hw *hw, int cap, u16 offset)
 {
-	unsigned long start = jiffies;
+	u32 val;
 
-	while ( (sky2_pci_read16(hw, cap + PCI_VPD_ADDR) & PCI_VPD_ADDR_F) == busy) {
-		/* Can take up to 10.6 ms for write */
-		if (time_after(jiffies, start + HZ/4)) {
-			dev_err(&hw->pdev->dev, PFX "VPD cycle timed out");
-			return -ETIMEDOUT;
-		}
-		mdelay(1);
-	}
-
-	return 0;
-}
-
-static int sky2_vpd_read(struct sky2_hw *hw, int cap, void *data,
-			 u16 offset, size_t length)
-{
-	int rc = 0;
-
-	while (length > 0) {
-		u32 val;
-
-		sky2_pci_write16(hw, cap + PCI_VPD_ADDR, offset);
-		rc = sky2_vpd_wait(hw, cap, 0);
-		if (rc)
-			break;
+	sky2_pci_write16(hw, cap + PCI_VPD_ADDR, offset);
 
-		val = sky2_pci_read32(hw, cap + PCI_VPD_DATA);
-
-		memcpy(data, &val, min(sizeof(val), length));
-		offset += sizeof(u32);
-		data += sizeof(u32);
-		length -= sizeof(u32);
-	}
+	do {
+		offset = sky2_pci_read16(hw, cap + PCI_VPD_ADDR);
+	} while (!(offset & PCI_VPD_ADDR_F));
 
-	return rc;
+	val = sky2_pci_read32(hw, cap + PCI_VPD_DATA);
+	return val;
 }
 
-static int sky2_vpd_write(struct sky2_hw *hw, int cap, const void *data,
-			  u16 offset, unsigned int length)
+static void sky2_vpd_write(struct sky2_hw *hw, int cap, u16 offset, u32 val)
 {
-	unsigned int i;
-	int rc = 0;
-
-	for (i = 0; i < length; i += sizeof(u32)) {
-		u32 val = *(u32 *)(data + i);
-
-		sky2_pci_write32(hw, cap + PCI_VPD_DATA, val);
-		sky2_pci_write32(hw, cap + PCI_VPD_ADDR, offset | PCI_VPD_ADDR_F);
-
-		rc = sky2_vpd_wait(hw, cap, PCI_VPD_ADDR_F);
-		if (rc)
-			break;
-	}
-	return rc;
+	sky2_pci_write16(hw, cap + PCI_VPD_DATA, val);
+	sky2_pci_write32(hw, cap + PCI_VPD_ADDR, offset | PCI_VPD_ADDR_F);
+	do {
+		offset = sky2_pci_read16(hw, cap + PCI_VPD_ADDR);
+	} while (offset & PCI_VPD_ADDR_F);
 }
 
 static int sky2_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
@@ -3822,13 +3786,24 @@ static int sky2_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom
 {
 	struct sky2_port *sky2 = netdev_priv(dev);
 	int cap = pci_find_capability(sky2->hw->pdev, PCI_CAP_ID_VPD);
+	int length = eeprom->len;
+	u16 offset = eeprom->offset;
 
 	if (!cap)
 		return -EINVAL;
 
 	eeprom->magic = SKY2_EEPROM_MAGIC;
 
-	return sky2_vpd_read(sky2->hw, cap, data, eeprom->offset, eeprom->len);
+	while (length > 0) {
+		u32 val = sky2_vpd_read(sky2->hw, cap, offset);
+		int n = min_t(int, length, sizeof(val));
+
+		memcpy(data, &val, n);
+		length -= n;
+		data += n;
+		offset += n;
+	}
+	return 0;
 }
 
 static int sky2_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
@@ -3836,6 +3811,8 @@ static int sky2_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom
 {
 	struct sky2_port *sky2 = netdev_priv(dev);
 	int cap = pci_find_capability(sky2->hw->pdev, PCI_CAP_ID_VPD);
+	int length = eeprom->len;
+	u16 offset = eeprom->offset;
 
 	if (!cap)
 		return -EINVAL;
@@ -3843,11 +3820,21 @@ static int sky2_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom
 	if (eeprom->magic != SKY2_EEPROM_MAGIC)
 		return -EINVAL;
 
-	/* Partial writes not supported */
-	if ((eeprom->offset & 3) || (eeprom->len & 3))
-		return -EINVAL;
+	while (length > 0) {
+		u32 val;
+		int n = min_t(int, length, sizeof(val));
+
+		if (n < sizeof(val))
+			val = sky2_vpd_read(sky2->hw, cap, offset);
+		memcpy(&val, data, n);
 
-	return sky2_vpd_write(sky2->hw, cap, data, eeprom->offset, eeprom->len);
+		sky2_vpd_write(sky2->hw, cap, offset, val);
+
+		length -= n;
+		data += n;
+		offset += n;
+	}
+	return 0;
 }
 
 
@@ -4203,69 +4190,6 @@ static int __devinit sky2_test_msi(struct sky2_hw *hw)
 	return err;
 }
 
-/*
- * Read and parse the first part of Vital Product Data
- */
-#define VPD_SIZE	128
-#define VPD_MAGIC	0x82
-
-static void __devinit sky2_vpd_info(struct sky2_hw *hw)
-{
-	int cap = pci_find_capability(hw->pdev, PCI_CAP_ID_VPD);
-	const u8 *p;
-	u8 *vpd_buf = NULL;
-	u16 len;
-	static struct vpd_tag {
-		char tag[2];
-		char *label;
-	} vpd_tags[] = {
-		{ "PN",	"Part Number" },
-		{ "EC", "Engineering Level" },
-		{ "MN", "Manufacturer" },
-	};
-
-	if (!cap)
-		goto out;
-
-	vpd_buf = kmalloc(VPD_SIZE, GFP_KERNEL);
-	if (!vpd_buf)
-		goto out;
-
-	if (sky2_vpd_read(hw, cap, vpd_buf, 0, VPD_SIZE))
-		goto out;
-
-	if (vpd_buf[0] != VPD_MAGIC)
-		goto out;
-	len = vpd_buf[1];
-	if (len == 0 || len > VPD_SIZE - 4)
-		goto out;
-	p = vpd_buf + 3;
-	dev_info(&hw->pdev->dev, "%.*s\n", len, p);
-	p += len;
-
-	while (p < vpd_buf + VPD_SIZE - 4) {
-		int i;
-
-		if (!memcmp("RW", p, 2))	/* end marker */
-			break;
-
-		len = p[2];
-		if (len > (p - vpd_buf) - 4)
-			break;
-
-		for (i = 0; i < ARRAY_SIZE(vpd_tags); i++) {
-			if (!memcmp(vpd_tags[i].tag, p, 2)) {
-				printk(KERN_DEBUG " %s: %.*s\n",
-				       vpd_tags[i].label, len, p + 3);
-				break;
-			}
-		}
-		p += len + 3;
-	}
-out:
-	kfree(vpd_buf);
-}
-
 /* This driver supports yukon2 chipset only */
 static const char *sky2_name(u8 chipid, char *buf, int sz)
 {
@@ -4364,13 +4288,13 @@ static int __devinit sky2_probe(struct pci_dev *pdev,
 	if (err)
 		goto err_out_iounmap;
 
-	dev_info(&pdev->dev, "Yukon-2 %s chip revision %d\n",
-		 sky2_name(hw->chip_id, buf1, sizeof(buf1)), hw->chip_rev);
+	dev_info(&pdev->dev, "v%s addr 0x%llx irq %d Yukon-2 %s rev %d\n",
+		 DRV_VERSION, (unsigned long long)pci_resource_start(pdev, 0),
+		 pdev->irq, sky2_name(hw->chip_id, buf1, sizeof(buf1)),
+		 hw->chip_rev);
 
 	sky2_reset(hw);
 
-	sky2_vpd_info(hw);
-
 	dev = sky2_init_netdev(hw, 0, using_dac, wol_default);
 	if (!dev) {
 		err = -ENOMEM;