From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: davem@davemloft.net
Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
netdev@vger.kernel.org, gospo@redhat.com,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: [net-next 08/11] ixgbe: Update TXDCTL configuration to correctly handle WTHRESH
Date: Thu, 15 Sep 2011 21:42:50 -0700 [thread overview]
Message-ID: <1316148173-11209-9-git-send-email-jeffrey.t.kirsher@intel.com> (raw)
In-Reply-To: <1316148173-11209-1-git-send-email-jeffrey.t.kirsher@intel.com>
From: Alexander Duyck <alexander.h.duyck@intel.com>
This change updated the TXDCTL configuration. The main goal is to be much
more explicit about the configuration and avoid a possible fake TX hang
when the interrupt throttle rate is set to 0.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 35 +++++++++++++------------
1 files changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index fee5630..6378d7f 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2359,13 +2359,11 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter *adapter,
struct ixgbe_hw *hw = &adapter->hw;
u64 tdba = ring->dma;
int wait_loop = 10;
- u32 txdctl;
+ u32 txdctl = IXGBE_TXDCTL_ENABLE;
u8 reg_idx = ring->reg_idx;
/* disable queue to avoid issues while updating state */
- txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(reg_idx));
- IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(reg_idx),
- txdctl & ~IXGBE_TXDCTL_ENABLE);
+ IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(reg_idx), 0);
IXGBE_WRITE_FLUSH(hw);
IXGBE_WRITE_REG(hw, IXGBE_TDBAL(reg_idx),
@@ -2377,18 +2375,22 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter *adapter,
IXGBE_WRITE_REG(hw, IXGBE_TDT(reg_idx), 0);
ring->tail = hw->hw_addr + IXGBE_TDT(reg_idx);
- /* configure fetching thresholds */
- if (adapter->rx_itr_setting == 0) {
- /* cannot set wthresh when itr==0 */
- txdctl &= ~0x007F0000;
- } else {
- /* enable WTHRESH=8 descriptors, to encourage burst writeback */
- txdctl |= (8 << 16);
- }
- if (adapter->flags & IXGBE_FLAG_DCB_ENABLED) {
- /* PThresh workaround for Tx hang with DFP enabled. */
- txdctl |= 32;
- }
+ /*
+ * set WTHRESH to encourage burst writeback, it should not be set
+ * higher than 1 when ITR is 0 as it could cause false TX hangs
+ *
+ * In order to avoid issues WTHRESH + PTHRESH should always be equal
+ * to or less than the number of on chip descriptors, which is
+ * currently 40.
+ */
+ if (!adapter->tx_itr_setting || !adapter->rx_itr_setting)
+ txdctl |= (1 << 16); /* WTHRESH = 1 */
+ else
+ txdctl |= (8 << 16); /* WTHRESH = 8 */
+
+ /* PTHRESH=32 is needed to avoid a Tx hang with DFP enabled. */
+ txdctl |= (1 << 8) | /* HTHRESH = 1 */
+ 32; /* PTHRESH = 32 */
/* reinitialize flowdirector state */
if ((adapter->flags & IXGBE_FLAG_FDIR_HASH_CAPABLE) &&
@@ -2403,7 +2405,6 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter *adapter,
clear_bit(__IXGBE_HANG_CHECK_ARMED, &ring->state);
/* enable queue */
- txdctl |= IXGBE_TXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(reg_idx), txdctl);
/* TXDCTL.EN will return 0 on 82598 if link is down, so skip it */
--
1.7.6
next prev parent reply other threads:[~2011-09-16 4:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-16 4:42 [net-next 00/11][pull request] Intel Wired LAN Driver Updates Jeff Kirsher
2011-09-16 4:42 ` [net-next 01/11] ixgbe: Change default Tx work limit size to 256 buffers Jeff Kirsher
2011-09-16 4:42 ` [net-next 02/11] v2 ixgbe: consolidate all MSI-X ring interrupts and poll routines into one Jeff Kirsher
2011-09-16 4:42 ` [net-next 03/11] ixgbe: cleanup allocation and freeing of IRQ affinity hint Jeff Kirsher
2011-09-16 4:42 ` [net-next 04/11] ixgbe: Use ring->dev instead of adapter->pdev->dev when updating DCA Jeff Kirsher
2011-09-16 4:42 ` [net-next 05/11] ixgbe: commonize ixgbe_map_rings_to_vectors to work for all interrupt types Jeff Kirsher
2011-09-16 4:42 ` [net-next 06/11] ixgbe: Drop unnecessary adapter->hw dereference in loopback test setup Jeff Kirsher
2011-09-16 4:42 ` [net-next 07/11] ixgbe: combine PCI_VDEVICE and board declaration to same line Jeff Kirsher
2011-09-16 4:42 ` Jeff Kirsher [this message]
2011-09-16 4:42 ` [net-next 09/11] ixgbe: cleanup reset paths Jeff Kirsher
2011-09-16 4:42 ` [net-next 10/11] ixgbe: cleanup configuration of EITRSEL and VF reset path Jeff Kirsher
2011-09-16 4:42 ` [net-next 11/11] ixgbe: Correctly name and handle MSI-X other interrupt Jeff Kirsher
2011-09-16 19:20 ` [net-next 00/11][pull request] Intel Wired LAN Driver Updates David Miller
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