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>
diff --git a/drivers/net/ixgbe/ixgbe_common.c b/drivers/net/ixgbe/ixgbe_common.c
index 777051f..fc1375f 100644
--- a/drivers/net/ixgbe/ixgbe_common.c
+++ b/drivers/net/ixgbe/ixgbe_common.c
@@ -2632,6 +2632,7 @@
autoc_reg |= IXGBE_AUTOC_AN_RESTART;
autoc_reg |= IXGBE_AUTOC_FLU;
IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc_reg);
+ IXGBE_WRITE_FLUSH(hw);
usleep_range(10000, 20000);
}
diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index dc64955..82d4244 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -1378,6 +1378,7 @@
/* Disable all the interrupts */
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMC, 0xFFFFFFFF);
+ IXGBE_WRITE_FLUSH(&adapter->hw);
usleep_range(10000, 20000);
/* Test each interrupt */
@@ -1398,6 +1399,7 @@
~mask & 0x00007FFF);
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EICS,
~mask & 0x00007FFF);
+ IXGBE_WRITE_FLUSH(&adapter->hw);
usleep_range(10000, 20000);
if (adapter->test_icr & mask) {
@@ -1415,6 +1417,7 @@
adapter->test_icr = 0;
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMS, mask);
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EICS, mask);
+ IXGBE_WRITE_FLUSH(&adapter->hw);
usleep_range(10000, 20000);
if (!(adapter->test_icr &mask)) {
@@ -1435,6 +1438,7 @@
~mask & 0x00007FFF);
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EICS,
~mask & 0x00007FFF);
+ IXGBE_WRITE_FLUSH(&adapter->hw);
usleep_range(10000, 20000);
if (adapter->test_icr) {
@@ -1446,6 +1450,7 @@
/* Disable all the interrupts */
IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMC, 0xFFFFFFFF);
+ IXGBE_WRITE_FLUSH(&adapter->hw);
usleep_range(10000, 20000);
/* Unhook test interrupt handler */
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 1be6175..26b132b 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -184,6 +184,7 @@
vmdctl = IXGBE_READ_REG(hw, IXGBE_VT_CTL);
vmdctl &= ~IXGBE_VT_CTL_POOL_MASK;
IXGBE_WRITE_REG(hw, IXGBE_VT_CTL, vmdctl);
+ IXGBE_WRITE_FLUSH(hw);
/* take a breather then clean up driver data */
msleep(100);
diff --git a/drivers/net/ixgbe/ixgbe_phy.c b/drivers/net/ixgbe/ixgbe_phy.c
index 735f686..f7ca351 100644
--- a/drivers/net/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ixgbe/ixgbe_phy.c
@@ -1585,6 +1585,7 @@
*i2cctl |= IXGBE_I2C_CLK_OUT;
IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+ IXGBE_WRITE_FLUSH(hw);
/* SCL rise time (1000ns) */
udelay(IXGBE_I2C_T_RISE);
@@ -1605,6 +1606,7 @@
*i2cctl &= ~IXGBE_I2C_CLK_OUT;
IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+ IXGBE_WRITE_FLUSH(hw);
/* SCL fall time (300ns) */
udelay(IXGBE_I2C_T_FALL);
@@ -1628,6 +1630,7 @@
*i2cctl &= ~IXGBE_I2C_DATA_OUT;
IXGBE_WRITE_REG(hw, IXGBE_I2CCTL, *i2cctl);
+ IXGBE_WRITE_FLUSH(hw);
/* Data rise/fall (1000ns/300ns) and set-up time (250ns) */
udelay(IXGBE_I2C_T_RISE + IXGBE_I2C_T_FALL + IXGBE_I2C_T_SU_DATA);
diff --git a/drivers/net/ixgbe/ixgbe_x540.c b/drivers/net/ixgbe/ixgbe_x540.c
index bec30ed..2696c78 100644
--- a/drivers/net/ixgbe/ixgbe_x540.c
+++ b/drivers/net/ixgbe/ixgbe_x540.c
@@ -162,6 +162,7 @@
ctrl_ext = IXGBE_READ_REG(hw, IXGBE_CTRL_EXT);
ctrl_ext |= IXGBE_CTRL_EXT_PFRSTD;
IXGBE_WRITE_REG(hw, IXGBE_CTRL_EXT, ctrl_ext);
+ IXGBE_WRITE_FLUSH(hw);
msleep(50);