From 5df3f0eaf8b236cc785e2733a3df1e5c84e4aad8 Mon Sep 17 00:00:00 2001 From: dave graham Date: Tue, 10 Feb 2009 12:51:41 +0000 Subject: e1000e: Disable dynamic clock gating for 82571 per si errata. 82571 and 82572 Errata #13 documents that the Si feature DMA Dynamic Clock Gating should be disabled, and identifies the workaround of disabling the feature by EEPROM setting. EEPROM versions that do not include the recommended workaround have been found in the field, and so some customers remain at risk. Because the feature DMA Dynamic clock Gating can be disabled by directly setting the appropriate bit in the E1000_CTRL_EXT register, this patch overrides the EEPROM setting, and force-disables the feature. Signed-off-by: dave graham Acked-by: Bruce Allan Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/e1000e/82571.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/net/e1000e/82571.c') diff --git a/drivers/net/e1000e/82571.c b/drivers/net/e1000e/82571.c index 0890162953e9..25f6bc94e69b 100644 --- a/drivers/net/e1000e/82571.c +++ b/drivers/net/e1000e/82571.c @@ -980,6 +980,18 @@ static void e1000_initialize_hw_bits_82571(struct e1000_hw *hw) reg |= E1000_PBA_ECC_CORR_EN; ew32(PBA_ECC, reg); } + /* + * Workaround for hardware errata. + * Ensure that DMA Dynamic Clock gating is disabled on 82571 and 82572 + */ + + if ((hw->mac.type == e1000_82571) || + (hw->mac.type == e1000_82572)) { + reg = er32(CTRL_EXT); + reg &= ~E1000_CTRL_EXT_DMA_DYN_CLK_EN; + ew32(CTRL_EXT, reg); + } + /* PCI-Ex Control Registers */ if (hw->mac.type == e1000_82574) { -- cgit