From 0c02dd983f0971813fcae81672b9533c35a5b2db Mon Sep 17 00:00:00 2001 From: Matthew Vick Date: Sat, 14 Apr 2012 05:20:32 +0000 Subject: [PATCH] igb: Disable the BMC-to-OS Watchdog Enable bit for DMAC. Under certain scenarios, it's possible that bursty manageability traffic over the BMC-to-OS path may overrun the internal manageability receive buffer causing dropped manageability packets. Clearing this bit prevents this situation by interrupting coalescing to allow manageability traffic through. Signed-off-by: Matthew Vick Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igb/e1000_defines.h | 2 ++ drivers/net/ethernet/intel/igb/igb_main.c | 3 +++ 2 files changed, 5 insertions(+) diff --git a/drivers/net/ethernet/intel/igb/e1000_defines.h b/drivers/net/ethernet/intel/igb/e1000_defines.h index 6409f85632f5..ec7e4fe3e3ee 100644 --- a/drivers/net/ethernet/intel/igb/e1000_defines.h +++ b/drivers/net/ethernet/intel/igb/e1000_defines.h @@ -301,6 +301,8 @@ * transactions */ #define E1000_DMACR_DMAC_LX_SHIFT 28 #define E1000_DMACR_DMAC_EN 0x80000000 /* Enable DMA Coalescing */ +/* DMA Coalescing BMC-to-OS Watchdog Enable */ +#define E1000_DMACR_DC_BMC2OSW_EN 0x00008000 #define E1000_DMCTXTH_DMCTTHR_MASK 0x00000FFF /* DMA Coalescing Transmit * Threshold */ diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 9bbf1a275947..dd3bfe8cd36c 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7147,6 +7147,9 @@ static void igb_init_dmac(struct igb_adapter *adapter, u32 pba) /* watchdog timer= +-1000 usec in 32usec intervals */ reg |= (1000 >> 5); + + /* Disable BMC-to-OS Watchdog Enable */ + reg &= ~E1000_DMACR_DC_BMC2OSW_EN; wr32(E1000_DMACR, reg); /*