From 1d2101a712b3b7281a19ff6d7bfc16c2ce9d3998 Mon Sep 17 00:00:00 2001 From: Bruce Allan Date: Fri, 22 Jul 2011 06:21:56 +0000 Subject: [PATCH] e1000e: Spurious interrupts & dropped packets with 82577/8/9 in half-duplex On 82577/8/9 in half-duplex when a received packet is passed from the PHY to the MAC, if too many preamble octects are stripped from the packet before arriving at the MAC, it can be misintrepeted as an in-band message rather than an actual frame. For example, if the frame contents resembled an interrupt request in-band message, it would trigger a false interrupt. In most cases, the packet is just dropped. By reducing the number of preamble octets stripped from the beginning of the frame when passing it from the PHY to the MAC, the MAC will interpret the frame properly. An additional uses of the magic PHY_REG(770, 16) have been updated with a define introduced with this patch. Signed-off-by: Bruce Allan Tested-by: Jeff Pieper Signed-off-by: Jeff Kirsher --- drivers/net/e1000e/ich8lan.c | 41 +++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c index 4e36978b8fd8..7525e372720c 100644 --- a/drivers/net/e1000e/ich8lan.c +++ b/drivers/net/e1000e/ich8lan.c @@ -163,6 +163,11 @@ #define HV_KMRN_MODE_CTRL PHY_REG(769, 16) #define HV_KMRN_MDIO_SLOW 0x0400 +/* KMRN FIFO Control and Status */ +#define HV_KMRN_FIFO_CTRLSTA PHY_REG(770, 16) +#define HV_KMRN_FIFO_CTRLSTA_PREAMBLE_MASK 0x7000 +#define HV_KMRN_FIFO_CTRLSTA_PREAMBLE_SHIFT 12 + /* ICH GbE Flash Hardware Sequencing Flash Status Register bit breakdown */ /* Offset 04h HSFSTS */ union ich8_hws_flash_status { @@ -657,6 +662,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) struct e1000_mac_info *mac = &hw->mac; s32 ret_val; bool link; + u16 phy_reg; /* * We only want to go out to the PHY registers to see if Auto-Neg @@ -689,16 +695,35 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) mac->get_link_status = false; - if (hw->phy.type == e1000_phy_82578) { - ret_val = e1000_link_stall_workaround_hv(hw); - if (ret_val) - goto out; - } - - if (hw->mac.type == e1000_pch2lan) { + switch (hw->mac.type) { + case e1000_pch2lan: ret_val = e1000_k1_workaround_lv(hw); if (ret_val) goto out; + /* fall-thru */ + case e1000_pchlan: + if (hw->phy.type == e1000_phy_82578) { + ret_val = e1000_link_stall_workaround_hv(hw); + if (ret_val) + goto out; + } + + /* + * Workaround for PCHx parts in half-duplex: + * Set the number of preambles removed from the packet + * when it is passed from the PHY to the MAC to prevent + * the MAC from misinterpreting the packet type. + */ + e1e_rphy(hw, HV_KMRN_FIFO_CTRLSTA, &phy_reg); + phy_reg &= ~HV_KMRN_FIFO_CTRLSTA_PREAMBLE_MASK; + + if ((er32(STATUS) & E1000_STATUS_FD) != E1000_STATUS_FD) + phy_reg |= (1 << HV_KMRN_FIFO_CTRLSTA_PREAMBLE_SHIFT); + + e1e_wphy(hw, HV_KMRN_FIFO_CTRLSTA, phy_reg); + break; + default: + break; } /* @@ -1355,7 +1380,7 @@ static s32 e1000_hv_phy_workarounds_ich8lan(struct e1000_hw *hw) return ret_val; /* Preamble tuning for SSC */ - ret_val = e1e_wphy(hw, PHY_REG(770, 16), 0xA204); + ret_val = e1e_wphy(hw, HV_KMRN_FIFO_CTRLSTA, 0xA204); if (ret_val) return ret_val; } -- 2.20.1