diff options
| author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2011-07-20 00:56:21 +0000 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2011-08-04 04:59:07 -0700 |
| commit | 945a51517cc0bd9e461f2018624dfc1faef9ddee (patch) | |
| tree | 5782ffe27f3fb8f5b4cbc19ffe7b74bff36c6a05 /drivers/net/e1000e/ich8lan.c | |
| parent | d3e614577198757d5854caa912e88f2d4296479b (diff) | |
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/e1000e/ich8lan.c')
| -rw-r--r-- | drivers/net/e1000e/ich8lan.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c index c1752124f3c..f7a75c1531a 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) |