From 945a51517cc0bd9e461f2018624dfc1faef9ddee Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg 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 Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/igb/igb_ethtool.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/net/igb/igb_ethtool.c') 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 */ -- cgit v1.2.3