1 files changed, 74 insertions, 43 deletions

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 1d586d4f7b56..9b166d70ae91 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -84,65 +84,92 @@ int usb_amd_find_chipset_info(void)
 {
 	u8 rev = 0;
 	unsigned long flags;
+	struct amd_chipset_info info;
+	int ret;
 
 	spin_lock_irqsave(&amd_lock, flags);
 
-	amd_chipset.probe_count++;
 	/* probe only once */
-	if (amd_chipset.probe_count > 1) {
+	if (amd_chipset.probe_count > 0) {
+		amd_chipset.probe_count++;
 		spin_unlock_irqrestore(&amd_lock, flags);
 		return amd_chipset.probe_result;
 	}
+	memset(&info, 0, sizeof(info));
+	spin_unlock_irqrestore(&amd_lock, flags);
 
-	amd_chipset.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
-	if (amd_chipset.smbus_dev) {
-		rev = amd_chipset.smbus_dev->revision;
+	info.smbus_dev = pci_get_device(PCI_VENDOR_ID_ATI, 0x4385, NULL);
+	if (info.smbus_dev) {
+		rev = info.smbus_dev->revision;
 		if (rev >= 0x40)
-			amd_chipset.sb_type = 1;
+			info.sb_type = 1;
 		else if (rev >= 0x30 && rev <= 0x3b)
-			amd_chipset.sb_type = 3;
+			info.sb_type = 3;
 	} else {
-		amd_chipset.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
-							0x780b, NULL);
-		if (!amd_chipset.smbus_dev) {
-			spin_unlock_irqrestore(&amd_lock, flags);
-			return 0;
+		info.smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
+						0x780b, NULL);
+		if (!info.smbus_dev) {
+			ret = 0;
+			goto commit;
 		}
-		rev = amd_chipset.smbus_dev->revision;
+
+		rev = info.smbus_dev->revision;
 		if (rev >= 0x11 && rev <= 0x18)
-			amd_chipset.sb_type = 2;
+			info.sb_type = 2;
 	}
 
-	if (amd_chipset.sb_type == 0) {
-		if (amd_chipset.smbus_dev) {
-			pci_dev_put(amd_chipset.smbus_dev);
-			amd_chipset.smbus_dev = NULL;
+	if (info.sb_type == 0) {
+		if (info.smbus_dev) {
+			pci_dev_put(info.smbus_dev);
+			info.smbus_dev = NULL;
 		}
-		spin_unlock_irqrestore(&amd_lock, flags);
-		return 0;
+		ret = 0;
+		goto commit;
 	}
 
-	amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
-	if (amd_chipset.nb_dev) {
-		amd_chipset.nb_type = 1;
+	info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x9601, NULL);
+	if (info.nb_dev) {
+		info.nb_type = 1;
 	} else {
-		amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
-							0x1510, NULL);
-		if (amd_chipset.nb_dev) {
-			amd_chipset.nb_type = 2;
-		} else  {
-			amd_chipset.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
-								0x9600, NULL);
-			if (amd_chipset.nb_dev)
-				amd_chipset.nb_type = 3;
+		info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x1510, NULL);
+		if (info.nb_dev) {
+			info.nb_type = 2;
+		} else {
+			info.nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
+						     0x9600, NULL);
+			if (info.nb_dev)
+				info.nb_type = 3;
 		}
 	}
 
-	amd_chipset.probe_result = 1;
+	ret = info.probe_result = 1;
 	printk(KERN_DEBUG "QUIRK: Enable AMD PLL fix\n");
 
-	spin_unlock_irqrestore(&amd_lock, flags);
-	return amd_chipset.probe_result;
+commit:
+
+	spin_lock_irqsave(&amd_lock, flags);
+	if (amd_chipset.probe_count > 0) {
+		/* race - someone else was faster - drop devices */
+
+		/* Mark that we where here */
+		amd_chipset.probe_count++;
+		ret = amd_chipset.probe_result;
+
+		spin_unlock_irqrestore(&amd_lock, flags);
+
+		if (info.nb_dev)
+			pci_dev_put(info.nb_dev);
+		if (info.smbus_dev)
+			pci_dev_put(info.smbus_dev);
+
+	} else {
+		/* no race - commit the result */
+		info.probe_count++;
+		amd_chipset = info;
+		spin_unlock_irqrestore(&amd_lock, flags);
+	}
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_amd_find_chipset_info);
 
@@ -284,6 +311,7 @@ EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_enable);
 
 void usb_amd_dev_put(void)
 {
+	struct pci_dev *nb, *smbus;
 	unsigned long flags;
 
 	spin_lock_irqsave(&amd_lock, flags);
@@ -294,20 +322,23 @@ void usb_amd_dev_put(void)
 		return;
 	}
 
-	if (amd_chipset.nb_dev) {
-		pci_dev_put(amd_chipset.nb_dev);
-		amd_chipset.nb_dev = NULL;
-	}
-	if (amd_chipset.smbus_dev) {
-		pci_dev_put(amd_chipset.smbus_dev);
-		amd_chipset.smbus_dev = NULL;
-	}
+	/* save them to pci_dev_put outside of spinlock */
+	nb    = amd_chipset.nb_dev;
+	smbus = amd_chipset.smbus_dev;
+
+	amd_chipset.nb_dev = NULL;
+	amd_chipset.smbus_dev = NULL;
 	amd_chipset.nb_type = 0;
 	amd_chipset.sb_type = 0;
 	amd_chipset.isoc_reqs = 0;
 	amd_chipset.probe_result = 0;
 
 	spin_unlock_irqrestore(&amd_lock, flags);
+
+	if (nb)
+		pci_dev_put(nb);
+	if (smbus)
+		pci_dev_put(smbus);
 }
 EXPORT_SYMBOL_GPL(usb_amd_dev_put);