From: Kiran Patil <kiran.pa...@intel.com>
This patch contains following changes:
- detection and recovery logic (issue SW interrupt) has been moved to
service_task from timeout function.
- added some more debug info from tx_timeout.
Logic to detect and recover TX queue hung is now two step process:
- service_task detects TX queue hung and sets a bit(hung_detected) if
it was not set.
- if bit was set (means this is back-back hung condition detected),
issue SW interrupt and clear the bit.
- napi_poll clears the bit unconditionally since it cleans TX/RX queues.
Change-ID: Ieed03a48927c845a988b3ff375090bf37caeb903
Signed-off-by: Kiran Patil <kiran.pa...@intel.com>
Tested-by: Andrew Bowers <andrewx.bow...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e.h | 3 +++
drivers/net/ethernet/intel/i40e/i40e_main.c | 36 ++++++++++++++++++++++-----
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 ++
drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 21 ++++++++++------
drivers/net/ethernet/intel/i40evf/i40e_txrx.h | 15 +++++++++++
5 files changed, 64 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h
b/drivers/net/ethernet/intel/i40e/i40e.h
index 0b9537b..dde7ae7 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -579,6 +579,9 @@ struct i40e_q_vector {
u8 num_ringpairs; /* total number of ring pairs in vector */
+#define I40E_Q_VECTOR_HUNG_DETECT 0 /* Bit Index for hung detection logic */
+ unsigned long hung_detected; /* Set/Reset for hung_detection logic */
+
cpumask_t affinity_mask;
struct rcu_head rcu; /* to avoid race with update stats on free */
char name[I40E_INT_NAME_STR_LEN];
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c
b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 9e6268b..e19a579 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4368,17 +4368,41 @@ static void i40e_detect_recover_hung_queue(int q_idx,
struct i40e_vsi *vsi)
else
val = rd32(&pf->hw, I40E_PFINT_DYN_CTL0);
+ /* Bail out if interrupts are disabled because napi_poll
+ * execution in-progress or will get scheduled soon.
+ * napi_poll cleans TX and RX queues and updates 'next_to_clean'.
+ */
+ if (!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK))
+ return;
+
head = i40e_get_head(tx_ring);
tx_pending = i40e_get_tx_pending(tx_ring);
- /* Interrupts are disabled and TX pending is non-zero,
- * trigger the SW interrupt (don't wait). Worst case
- * there will be one extra interrupt which may result
- * into not cleaning any queues because queues are cleaned.
+ /* HW is done executing descriptors, updated HEAD write back,
+ * but SW hasn't processed those descriptors. If interrupt is
+ * not generated from this point ON, it could result into
+ * dev_watchdog detecting timeout on those netdev_queue,
+ * hence proactively trigger SW interrupt.
*/
- if (tx_pending && (!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK)))
- i40e_force_wb(vsi, tx_ring->q_vector);
+ if (tx_pending) {
+ /* NAPI Poll didn't run and clear since it was set */
+ if (test_and_clear_bit(I40E_Q_VECTOR_HUNG_DETECT,
+ &tx_ring->q_vector->hung_detected)) {
+ netdev_info(vsi->netdev, "VSI_seid %d, Hung TX queue
%d, tx_pending: %d, NTC:0x%x, HWB: 0x%x, NTU: 0x%x, TAIL: 0x%x\n",
+ vsi->seid, q_idx, tx_pending,
+ tx_ring->next_to_clean, head,
+ tx_ring->next_to_use,
+ readl(tx_ring->tail));
+ netdev_info(vsi->netdev, "VSI_seid %d, Issuing force_wb
for TX queue %d, Interrupt Reg: 0x%x\n",
+ vsi->seid, q_idx, val);
+ i40e_force_wb(vsi, tx_ring->q_vector);
+ } else {
+ /* First Chance - detected possible hung */
+ set_bit(I40E_Q_VECTOR_HUNG_DETECT,
+ &tx_ring->q_vector->hung_detected);
+ }
+ }
}
/**
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 7371df7..1d7d01c 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1891,6 +1891,8 @@ int i40e_napi_poll(struct napi_struct *napi, int budget)
return 0;
}
+ /* Clear hung_detected bit */
+ clear_bit(I40E_Q_VECTOR_HUNG_DETECT, &q_vector->hung_detected);
/* Since the actual Tx work is minimal, we can give the Tx a larger
* budget and be more aggressive about cleaning up the Tx descriptors.
*/
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 11561b6..06b6636 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -127,17 +127,24 @@ void i40evf_free_tx_resources(struct i40e_ring *tx_ring)
}
/**
- * i40e_get_head - Retrieve head from head writeback
- * @tx_ring: tx ring to fetch head of
+ * i40evf_get_tx_pending - how many Tx descriptors not processed
+ * @tx_ring: the ring of descriptors
*
- * Returns value of Tx ring head based on value stored
- * in head write-back location
+ * Since there is no access to the ring head register
+ * in XL710, we need to use our local copies
**/
-static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
+u32 i40evf_get_tx_pending(struct i40e_ring *ring)
{
- void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
+ u32 head, tail;
- return le32_to_cpu(*(volatile __le32 *)head);
+ head = i40e_get_head(ring);
+ tail = readl(ring->tail);
+
+ if (head != tail)
+ return (head < tail) ?
+ tail - head : (tail + ring->count - head);
+
+ return 0;
}
#define WB_STRIDE 0x3
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index 929ddd9..e29bb3e 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -324,4 +324,19 @@ int i40evf_setup_rx_descriptors(struct i40e_ring *rx_ring);
void i40evf_free_tx_resources(struct i40e_ring *tx_ring);
void i40evf_free_rx_resources(struct i40e_ring *rx_ring);
int i40evf_napi_poll(struct napi_struct *napi, int budget);
+u32 i40evf_get_tx_pending(struct i40e_ring *ring);
+
+/**
+ * i40e_get_head - Retrieve head from head writeback
+ * @tx_ring: Tx ring to fetch head of
+ *
+ * Returns value of Tx ring head based on value stored
+ * in head write-back location
+ **/
+static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
+{
+ void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
+
+ return le32_to_cpu(*(volatile __le32 *)head);
+}
#endif /* _I40E_TXRX_H_ */
--
2.5.0
--
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