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>

5 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/e1000e/es2lan.c b/drivers/net/e1000e/es2lan.c
index c0ecb2d9fdb7..e4f42257c24c 100644
--- a/drivers/net/e1000e/es2lan.c
+++ b/drivers/net/e1000e/es2lan.c
@@ -1313,6 +1313,7 @@ static s32 e1000_read_kmrn_reg_80003es2lan(struct e1000_hw *hw, u32 offset,
         kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
                        E1000_KMRNCTRLSTA_OFFSET) | E1000_KMRNCTRLSTA_REN;
         ew32(KMRNCTRLSTA, kmrnctrlsta);
+        e1e_flush();
 
         udelay(2);
 
@@ -1347,6 +1348,7 @@ static s32 e1000_write_kmrn_reg_80003es2lan(struct e1000_hw *hw, u32 offset,
         kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
                        E1000_KMRNCTRLSTA_OFFSET) | data;
         ew32(KMRNCTRLSTA, kmrnctrlsta);
+        e1e_flush();
 
         udelay(2);
 
diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index cb1a3623253e..72756e4e6448 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -964,6 +964,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 
         /* Disable all the interrupts */
         ew32(IMC, 0xFFFFFFFF);
+        e1e_flush();
         usleep_range(10000, 20000);
 
         /* Test each interrupt */
@@ -996,6 +997,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
                         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 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
                 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 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
                         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 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 
         /* Disable all the interrupts */
         ew32(IMC, 0xFFFFFFFF);
+        e1e_flush();
         usleep_range(10000, 20000);
 
         /* Unhook test interrupt handler */
@@ -1276,6 +1281,7 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
                              E1000_CTRL_FD);     /* Force Duplex to FULL */
 
                 ew32(CTRL, ctrl_reg);
+                e1e_flush();
                 udelay(500);
 
                 return 0;
@@ -1418,6 +1424,7 @@ static int e1000_set_82571_fiber_loopback(struct e1000_adapter *adapter)
          */
 #define E1000_SERDES_LB_ON 0x410
         ew32(SCTL, E1000_SERDES_LB_ON);
+        e1e_flush();
         usleep_range(10000, 20000);
 
         return 0;
@@ -1513,6 +1520,7 @@ static void e1000_loopback_cleanup(struct e1000_adapter *adapter)
                     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 @@ static int e1000_run_loopback_test(struct e1000_adapter *adapter)
                                 k = 0;
                 }
                 ew32(TDT, k);
+                e1e_flush();
                 msleep(200);
                 time = jiffies; /* set the start time for the receive */
                 good_cnt = 0;
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index c1752124f3cd..f7a75c1531ad 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -283,6 +283,7 @@ static void e1000_toggle_lanphypc_value_ich8lan(struct e1000_hw *hw)
         ctrl |= E1000_CTRL_LANPHYPC_OVERRIDE;
         ctrl &= ~E1000_CTRL_LANPHYPC_VALUE;
         ew32(CTRL, ctrl);
+        e1e_flush();
         udelay(10);
         ctrl &= ~E1000_CTRL_LANPHYPC_OVERRIDE;
         ew32(CTRL, ctrl);
@@ -1230,9 +1231,11 @@ s32 e1000_configure_k1_ich8lan(struct e1000_hw *hw, bool k1_enable)
         ew32(CTRL, reg);
 
         ew32(CTRL_EXT, ctrl_ext | E1000_CTRL_EXT_SPD_BYPS);
+        e1e_flush();
         udelay(20);
         ew32(CTRL, ctrl_reg);
         ew32(CTRL_EXT, ctrl_ext);
+        e1e_flush();
         udelay(20);
 
 out:
@@ -3090,6 +3093,7 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
         ret_val = e1000_acquire_swflag_ich8lan(hw);
         e_dbg("Issuing a global reset to ich8lan\n");
         ew32(CTRL, (ctrl | E1000_CTRL_RST));
+        /* cannot issue a flush here because it hangs the hardware */
         msleep(20);
 
         if (!ret_val)
diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index 65580b405942..7898a67d6505 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -1986,6 +1986,7 @@ static s32 e1000_ready_nvm_eeprom(struct e1000_hw *hw)
                 /* Clear SK and CS */
                 eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
                 ew32(EECD, eecd);
+                e1e_flush();
                 udelay(1);
 
                 /*
diff --git a/drivers/net/e1000e/phy.c b/drivers/net/e1000e/phy.c
index 2a6ee13285b1..8666476cb9be 100644
--- a/drivers/net/e1000e/phy.c
+++ b/drivers/net/e1000e/phy.c
@@ -537,6 +537,7 @@ static s32 __e1000_read_kmrn_reg(struct e1000_hw *hw, u32 offset, u16 *data,
         kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
                        E1000_KMRNCTRLSTA_OFFSET) | E1000_KMRNCTRLSTA_REN;
         ew32(KMRNCTRLSTA, kmrnctrlsta);
+        e1e_flush();
 
         udelay(2);
 
@@ -609,6 +610,7 @@ static s32 __e1000_write_kmrn_reg(struct e1000_hw *hw, u32 offset, u16 data,
         kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
                        E1000_KMRNCTRLSTA_OFFSET) | data;
         ew32(KMRNCTRLSTA, kmrnctrlsta);
+        e1e_flush();
 
         udelay(2);