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/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index cb1a362..72756e4 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -964,6 +964,7 @@
/* Disable all the interrupts */
ew32(IMC, 0xFFFFFFFF);
+ e1e_flush();
usleep_range(10000, 20000);
/* Test each interrupt */
@@ -996,6 +997,7 @@
adapter->test_icr = 0;
ew32(IMC, mask);
ew32(ICS, mask);
+ e1e_flush();
usleep_range(10000, 20000);
if (adapter->test_icr & mask) {
@@ -1014,6 +1016,7 @@
adapter->test_icr = 0;
ew32(IMS, mask);
ew32(ICS, mask);
+ e1e_flush();
usleep_range(10000, 20000);
if (!(adapter->test_icr & mask)) {
@@ -1032,6 +1035,7 @@
adapter->test_icr = 0;
ew32(IMC, ~mask & 0x00007FFF);
ew32(ICS, ~mask & 0x00007FFF);
+ e1e_flush();
usleep_range(10000, 20000);
if (adapter->test_icr) {
@@ -1043,6 +1047,7 @@
/* Disable all the interrupts */
ew32(IMC, 0xFFFFFFFF);
+ e1e_flush();
usleep_range(10000, 20000);
/* Unhook test interrupt handler */
@@ -1276,6 +1281,7 @@
E1000_CTRL_FD); /* Force Duplex to FULL */
ew32(CTRL, ctrl_reg);
+ e1e_flush();
udelay(500);
return 0;
@@ -1418,6 +1424,7 @@
*/
#define E1000_SERDES_LB_ON 0x410
ew32(SCTL, E1000_SERDES_LB_ON);
+ e1e_flush();
usleep_range(10000, 20000);
return 0;
@@ -1513,6 +1520,7 @@
hw->phy.media_type == e1000_media_type_internal_serdes) {
#define E1000_SERDES_LB_OFF 0x400
ew32(SCTL, E1000_SERDES_LB_OFF);
+ e1e_flush();
usleep_range(10000, 20000);
break;
}
@@ -1592,6 +1600,7 @@
k = 0;
}
ew32(TDT, k);
+ e1e_flush();
msleep(200);
time = jiffies; /* set the start time for the receive */
good_cnt = 0;