diff options
| author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2011-07-20 04:56:21 +0400 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2011-08-04 15:59:07 +0400 |
| commit | 945a51517cc0bd9e461f2018624dfc1faef9ddee (patch) | |
| tree | 5782ffe27f3fb8f5b4cbc19ffe7b74bff36c6a05 /drivers/net/e1000/e1000_ethtool.c | |
| parent | d3e614577198757d5854caa912e88f2d4296479b (diff) | |
| download | linux-945a51517cc0bd9e461f2018624dfc1faef9ddee.tar.xz | |
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>
Diffstat (limited to 'drivers/net/e1000/e1000_ethtool.c')
| -rw-r--r-- | drivers/net/e1000/e1000_ethtool.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c index c5f0f04219f3..5548d464261a 100644 --- a/drivers/net/e1000/e1000_ethtool.c +++ b/drivers/net/e1000/e1000_ethtool.c @@ -838,6 +838,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data) /* Disable all the interrupts */ ew32(IMC, 0xFFFFFFFF); + E1000_WRITE_FLUSH(); msleep(10); /* Test each interrupt */ @@ -856,6 +857,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data) adapter->test_icr = 0; ew32(IMC, mask); ew32(ICS, mask); + E1000_WRITE_FLUSH(); msleep(10); if (adapter->test_icr & mask) { @@ -873,6 +875,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data) adapter->test_icr = 0; ew32(IMS, mask); ew32(ICS, mask); + E1000_WRITE_FLUSH(); msleep(10); if (!(adapter->test_icr & mask)) { @@ -890,6 +893,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data) adapter->test_icr = 0; ew32(IMC, ~mask & 0x00007FFF); ew32(ICS, ~mask & 0x00007FFF); + E1000_WRITE_FLUSH(); msleep(10); if (adapter->test_icr) { @@ -901,6 +905,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data) /* Disable all the interrupts */ ew32(IMC, 0xFFFFFFFF); + E1000_WRITE_FLUSH(); msleep(10); /* Unhook test interrupt handler */ @@ -1394,6 +1399,7 @@ static int e1000_run_loopback_test(struct e1000_adapter *adapter) if (unlikely(++k == txdr->count)) k = 0; } ew32(TDT, k); + E1000_WRITE_FLUSH(); msleep(200); time = jiffies; /* set the start time for the receive */ good_cnt = 0; |