From 945a51517cc0bd9e461f2018624dfc1faef9ddee Mon Sep 17 00:00:00 2001
From: Jesse Brandeburg <jesse.brandeburg@intel.com>
Date: Wed, 20 Jul 2011 00:56:21 +0000
Subject: intel drivers: repair missing flush operations

after review of all intel drivers, found several instances where
drivers had the incorrect pattern of:
memory mapped write();
delay();

which should always be:
memory mapped write();
write flush(); /* aka memory mapped read */
delay();

explanation:
The reason for including the flush is that writes can be held
(posted) in PCI/PCIe bridges, but the read always has to complete
synchronously and therefore has to flush all pending writes to a
device.  If a write is held and followed by a delay, the delay
means nothing because the write may not have reached hardware
(maybe even not until the next read)

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by:  Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/igb/e1000_nvm.c   | 1 +
 drivers/net/igb/igb_ethtool.c | 5 +++++
 drivers/net/igb/igb_main.c    | 2 ++
 3 files changed, 8 insertions(+)

(limited to 'drivers/net/igb')

diff --git a/drivers/net/igb/e1000_nvm.c b/drivers/net/igb/e1000_nvm.c
index 7dcd65cede56..40407124e722 100644
--- a/drivers/net/igb/e1000_nvm.c
+++ b/drivers/net/igb/e1000_nvm.c
@@ -285,6 +285,7 @@ static s32 igb_ready_nvm_eeprom(struct e1000_hw *hw)
 		/* Clear SK and CS */
 		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
 		wr32(E1000_EECD, eecd);
+		wrfl();
 		udelay(1);
 		timeout = NVM_MAX_RETRY_SPI;
 
diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index ff244ce803ce..414b0225be89 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -1225,6 +1225,7 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
 
 	/* Disable all the interrupts */
 	wr32(E1000_IMC, ~0);
+	wrfl();
 	msleep(10);
 
 	/* Define all writable bits for ICS */
@@ -1268,6 +1269,7 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
 
 			wr32(E1000_IMC, mask);
 			wr32(E1000_ICS, mask);
+			wrfl();
 			msleep(10);
 
 			if (adapter->test_icr & mask) {
@@ -1289,6 +1291,7 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
 
 		wr32(E1000_IMS, mask);
 		wr32(E1000_ICS, mask);
+		wrfl();
 		msleep(10);
 
 		if (!(adapter->test_icr & mask)) {
@@ -1310,6 +1313,7 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
 
 			wr32(E1000_IMC, ~mask);
 			wr32(E1000_ICS, ~mask);
+			wrfl();
 			msleep(10);
 
 			if (adapter->test_icr & mask) {
@@ -1321,6 +1325,7 @@ static int igb_intr_test(struct igb_adapter *adapter, u64 *data)
 
 	/* Disable all the interrupts */
 	wr32(E1000_IMC, ~0);
+	wrfl();
 	msleep(10);
 
 	/* Unhook test interrupt handler */
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index dc599059512a..ae3937e8cdef 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -1052,6 +1052,7 @@ msi_only:
 		kfree(adapter->vf_data);
 		adapter->vf_data = NULL;
 		wr32(E1000_IOVCTL, E1000_IOVCTL_REUSE_VFQ);
+		wrfl();
 		msleep(100);
 		dev_info(&adapter->pdev->dev, "IOV Disabled\n");
 	}
@@ -2198,6 +2199,7 @@ static void __devexit igb_remove(struct pci_dev *pdev)
 		kfree(adapter->vf_data);
 		adapter->vf_data = NULL;
 		wr32(E1000_IOVCTL, E1000_IOVCTL_REUSE_VFQ);
+		wrfl();
 		msleep(100);
 		dev_info(&pdev->dev, "IOV Disabled\n");
 	}
-- 
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