diff options
author | Carolyn Wyborny <carolyn.wyborny@intel.com> | 2011-03-11 20:43:54 -0800 |
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committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2011-03-12 04:09:55 -0800 |
commit | 831ec0b4226cec7ea34f5c4c9810e78aeb2069bf (patch) | |
tree | 3576b08f16304217c5353b5a6aa2fa5ba5350187 /drivers/net/igb/igb_main.c | |
parent | 4322e561a93ec7ee034b603a6c610e7be90d4e8a (diff) | |
download | op-kernel-dev-831ec0b4226cec7ea34f5c4c9810e78aeb2069bf.zip op-kernel-dev-831ec0b4226cec7ea34f5c4c9810e78aeb2069bf.tar.gz |
igb: Add DMA Coalescing feature to driver
This patch add DMA Coalescing which is a power-saving feature that
coalesces DMA writes in order to stay in a low-power state as much
as possible. Feature is disabled by default.
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/igb/igb_main.c')
-rw-r--r-- | drivers/net/igb/igb_main.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 8c6af11..49476f7 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -1674,7 +1674,58 @@ void igb_reset(struct igb_adapter *adapter) if (hw->mac.ops.init_hw(hw)) dev_err(&pdev->dev, "Hardware Error\n"); + if (hw->mac.type > e1000_82580) { + if (adapter->flags & IGB_FLAG_DMAC) { + u32 reg; + /* + * DMA Coalescing high water mark needs to be higher + * than * the * Rx threshold. The Rx threshold is + * currently * pba - 6, so we * should use a high water + * mark of pba * - 4. */ + hwm = (pba - 4) << 10; + + reg = (((pba-6) << E1000_DMACR_DMACTHR_SHIFT) + & E1000_DMACR_DMACTHR_MASK); + + /* transition to L0x or L1 if available..*/ + reg |= (E1000_DMACR_DMAC_EN | E1000_DMACR_DMAC_LX_MASK); + + /* watchdog timer= +-1000 usec in 32usec intervals */ + reg |= (1000 >> 5); + wr32(E1000_DMACR, reg); + + /* no lower threshold to disable coalescing(smart fifb) + * -UTRESH=0*/ + wr32(E1000_DMCRTRH, 0); + + /* set hwm to PBA - 2 * max frame size */ + wr32(E1000_FCRTC, hwm); + + /* + * This sets the time to wait before requesting tran- + * sition to * low power state to number of usecs needed + * to receive 1 512 * byte frame at gigabit line rate + */ + reg = rd32(E1000_DMCTLX); + reg |= IGB_DMCTLX_DCFLUSH_DIS; + + /* Delay 255 usec before entering Lx state. */ + reg |= 0xFF; + wr32(E1000_DMCTLX, reg); + + /* free space in Tx packet buffer to wake from DMAC */ + wr32(E1000_DMCTXTH, + (IGB_MIN_TXPBSIZE - + (IGB_TX_BUF_4096 + adapter->max_frame_size)) + >> 6); + + /* make low power state decision controlled by DMAC */ + reg = rd32(E1000_PCIEMISC); + reg |= E1000_PCIEMISC_LX_DECISION; + wr32(E1000_PCIEMISC, reg); + } /* end if IGB_FLAG_DMAC set */ + } if (hw->mac.type == e1000_82580) { u32 reg = rd32(E1000_PCIEMISC); wr32(E1000_PCIEMISC, @@ -2157,6 +2208,9 @@ static void __devinit igb_probe_vfs(struct igb_adapter * adapter) random_ether_addr(mac_addr); igb_set_vf_mac(adapter, i, mac_addr); } + /* DMA Coalescing is not supported in IOV mode. */ + if (adapter->flags & IGB_FLAG_DMAC) + adapter->flags &= ~IGB_FLAG_DMAC; } #endif /* CONFIG_PCI_IOV */ } @@ -2331,6 +2385,9 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter) /* Explicitly disable IRQ since the NIC can be in any state. */ igb_irq_disable(adapter); + if (hw->mac.type == e1000_i350) + adapter->flags &= ~IGB_FLAG_DMAC; + set_bit(__IGB_DOWN, &adapter->state); return 0; } |