ixgbe: avoid HW lockup when adapter is reset with Tx work pending
This change is meant to avoid a hardware lockup when Tx work is still
pending and we request a reset.
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index 91986af..84ed9ef 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
@@ -61,6 +61,7 @@
u16 words, u16 *data);
static s32 ixgbe_detect_eeprom_page_size_generic(struct ixgbe_hw *hw,
u16 offset);
+static s32 ixgbe_disable_pcie_master(struct ixgbe_hw *hw);
/**
* ixgbe_start_hw_generic - Prepare hardware for Tx/Rx
@@ -496,7 +497,6 @@
**/
s32 ixgbe_stop_adapter_generic(struct ixgbe_hw *hw)
{
- u32 number_of_queues;
u32 reg_val;
u16 i;
@@ -507,35 +507,35 @@
hw->adapter_stopped = true;
/* Disable the receive unit */
- reg_val = IXGBE_READ_REG(hw, IXGBE_RXCTRL);
- reg_val &= ~(IXGBE_RXCTRL_RXEN);
- IXGBE_WRITE_REG(hw, IXGBE_RXCTRL, reg_val);
- IXGBE_WRITE_FLUSH(hw);
- usleep_range(2000, 4000);
+ IXGBE_WRITE_REG(hw, IXGBE_RXCTRL, 0);
- /* Clear interrupt mask to stop from interrupts being generated */
+ /* Clear interrupt mask to stop interrupts from being generated */
IXGBE_WRITE_REG(hw, IXGBE_EIMC, IXGBE_IRQ_CLEAR_MASK);
- /* Clear any pending interrupts */
+ /* Clear any pending interrupts, flush previous writes */
IXGBE_READ_REG(hw, IXGBE_EICR);
/* Disable the transmit unit. Each queue must be disabled. */
- number_of_queues = hw->mac.max_tx_queues;
- for (i = 0; i < number_of_queues; i++) {
- reg_val = IXGBE_READ_REG(hw, IXGBE_TXDCTL(i));
- if (reg_val & IXGBE_TXDCTL_ENABLE) {
- reg_val &= ~IXGBE_TXDCTL_ENABLE;
- IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(i), reg_val);
- }
+ for (i = 0; i < hw->mac.max_tx_queues; i++)
+ IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(i), IXGBE_TXDCTL_SWFLSH);
+
+ /* Disable the receive unit by stopping each queue */
+ for (i = 0; i < hw->mac.max_rx_queues; i++) {
+ reg_val = IXGBE_READ_REG(hw, IXGBE_RXDCTL(i));
+ reg_val &= ~IXGBE_RXDCTL_ENABLE;
+ reg_val |= IXGBE_RXDCTL_SWFLSH;
+ IXGBE_WRITE_REG(hw, IXGBE_RXDCTL(i), reg_val);
}
+ /* flush all queues disables */
+ IXGBE_WRITE_FLUSH(hw);
+ usleep_range(1000, 2000);
+
/*
* Prevent the PCI-E bus from from hanging by disabling PCI-E master
* access and verify no pending requests
*/
- ixgbe_disable_pcie_master(hw);
-
- return 0;
+ return ixgbe_disable_pcie_master(hw);
}
/**
@@ -2458,75 +2458,57 @@
* bit hasn't caused the master requests to be disabled, else 0
* is returned signifying master requests disabled.
**/
-s32 ixgbe_disable_pcie_master(struct ixgbe_hw *hw)
+static s32 ixgbe_disable_pcie_master(struct ixgbe_hw *hw)
{
struct ixgbe_adapter *adapter = hw->back;
- u32 i;
- u32 reg_val;
- u32 number_of_queues;
s32 status = 0;
- u16 dev_status = 0;
+ u32 i;
+ u16 value;
- /* Just jump out if bus mastering is already disabled */
+ /* Always set this bit to ensure any future transactions are blocked */
+ IXGBE_WRITE_REG(hw, IXGBE_CTRL, IXGBE_CTRL_GIO_DIS);
+
+ /* Exit if master requests are blocked */
if (!(IXGBE_READ_REG(hw, IXGBE_STATUS) & IXGBE_STATUS_GIO))
goto out;
- /* Disable the receive unit by stopping each queue */
- number_of_queues = hw->mac.max_rx_queues;
- for (i = 0; i < number_of_queues; i++) {
- reg_val = IXGBE_READ_REG(hw, IXGBE_RXDCTL(i));
- if (reg_val & IXGBE_RXDCTL_ENABLE) {
- reg_val &= ~IXGBE_RXDCTL_ENABLE;
- IXGBE_WRITE_REG(hw, IXGBE_RXDCTL(i), reg_val);
- }
- }
-
- reg_val = IXGBE_READ_REG(hw, IXGBE_CTRL);
- reg_val |= IXGBE_CTRL_GIO_DIS;
- IXGBE_WRITE_REG(hw, IXGBE_CTRL, reg_val);
-
+ /* Poll for master request bit to clear */
for (i = 0; i < IXGBE_PCI_MASTER_DISABLE_TIMEOUT; i++) {
+ udelay(100);
if (!(IXGBE_READ_REG(hw, IXGBE_STATUS) & IXGBE_STATUS_GIO))
- goto check_device_status;
- udelay(100);
+ goto out;
}
- hw_dbg(hw, "GIO Master Disable bit didn't clear - requesting resets\n");
- status = IXGBE_ERR_MASTER_REQUESTS_PENDING;
-
- /*
- * Before proceeding, make sure that the PCIe block does not have
- * transactions pending.
- */
-check_device_status:
- for (i = 0; i < IXGBE_PCI_MASTER_DISABLE_TIMEOUT; i++) {
- pci_read_config_word(adapter->pdev, IXGBE_PCI_DEVICE_STATUS,
- &dev_status);
- if (!(dev_status & IXGBE_PCI_DEVICE_STATUS_TRANSACTION_PENDING))
- break;
- udelay(100);
- }
-
- if (i == IXGBE_PCI_MASTER_DISABLE_TIMEOUT)
- hw_dbg(hw, "PCIe transaction pending bit also did not clear.\n");
- else
- goto out;
-
/*
* Two consecutive resets are required via CTRL.RST per datasheet
* 5.2.5.3.2 Master Disable. We set a flag to inform the reset routine
* of this need. The first reset prevents new master requests from
- * being issued by our device. We then must wait 1usec for any
+ * being issued by our device. We then must wait 1usec or more for any
* remaining completions from the PCIe bus to trickle in, and then reset
* again to clear out any effects they may have had on our device.
*/
- hw->mac.flags |= IXGBE_FLAGS_DOUBLE_RESET_REQUIRED;
+ hw_dbg(hw, "GIO Master Disable bit didn't clear - requesting resets\n");
+ hw->mac.flags |= IXGBE_FLAGS_DOUBLE_RESET_REQUIRED;
+
+ /*
+ * Before proceeding, make sure that the PCIe block does not have
+ * transactions pending.
+ */
+ for (i = 0; i < IXGBE_PCI_MASTER_DISABLE_TIMEOUT; i++) {
+ udelay(100);
+ pci_read_config_word(adapter->pdev, IXGBE_PCI_DEVICE_STATUS,
+ &value);
+ if (!(value & IXGBE_PCI_DEVICE_STATUS_TRANSACTION_PENDING))
+ goto out;
+ }
+
+ hw_dbg(hw, "PCIe transaction pending bit also did not clear.\n");
+ status = IXGBE_ERR_MASTER_REQUESTS_PENDING;
out:
return status;
}
-
/**
* ixgbe_acquire_swfw_sync - Acquire SWFW semaphore
* @hw: pointer to hardware structure
@@ -3509,3 +3491,44 @@
out:
return ret_val;
}
+
+/**
+ * ixgbe_clear_tx_pending - Clear pending TX work from the PCIe fifo
+ * @hw: pointer to the hardware structure
+ *
+ * The 82599 and x540 MACs can experience issues if TX work is still pending
+ * when a reset occurs. This function prevents this by flushing the PCIe
+ * buffers on the system.
+ **/
+void ixgbe_clear_tx_pending(struct ixgbe_hw *hw)
+{
+ u32 gcr_ext, hlreg0;
+
+ /*
+ * If double reset is not requested then all transactions should
+ * already be clear and as such there is no work to do
+ */
+ if (!(hw->mac.flags & IXGBE_FLAGS_DOUBLE_RESET_REQUIRED))
+ return;
+
+ /*
+ * Set loopback enable to prevent any transmits from being sent
+ * should the link come up. This assumes that the RXCTRL.RXEN bit
+ * has already been cleared.
+ */
+ hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
+ IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0 | IXGBE_HLREG0_LPBK);
+
+ /* initiate cleaning flow for buffers in the PCIe transaction layer */
+ gcr_ext = IXGBE_READ_REG(hw, IXGBE_GCR_EXT);
+ IXGBE_WRITE_REG(hw, IXGBE_GCR_EXT,
+ gcr_ext | IXGBE_GCR_EXT_BUFFERS_CLEAR);
+
+ /* Flush all writes and allow 20usec for all transactions to clear */
+ IXGBE_WRITE_FLUSH(hw);
+ udelay(20);
+
+ /* restore previous register values */
+ IXGBE_WRITE_REG(hw, IXGBE_GCR_EXT, gcr_ext);
+ IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);
+}