iwlagn: add IRQ tracing

The legacy IRQs could be read from a trace by their
IO accesses, but reading the ICT doesn't leave any
trace (pun intended ;-) ) so in order to see what
input they get we need to add specific tracepoints.

While at it, fix whitespace in two related places.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

2 files changed, 50 insertions, 11 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-devtrace.h b/drivers/net/wireless/iwlwifi/iwl-devtrace.h
index f9d3319ecad5..9b212a8f30bb 100644
--- a/drivers/net/wireless/iwlwifi/iwl-devtrace.h
+++ b/drivers/net/wireless/iwlwifi/iwl-devtrace.h
@@ -90,6 +90,35 @@ TRACE_EVENT(iwlwifi_dev_iowrite32,
         TP_printk("[%p] write io[%#x] = %#x)", __entry->priv, __entry->offs, __entry->val)
 );
 
+TRACE_EVENT(iwlwifi_dev_irq,
+        TP_PROTO(void *priv),
+        TP_ARGS(priv),
+        TP_STRUCT__entry(
+                PRIV_ENTRY
+        ),
+        TP_fast_assign(
+                PRIV_ASSIGN;
+        ),
+        /* TP_printk("") doesn't compile */
+        TP_printk("%d", 0)
+);
+
+TRACE_EVENT(iwlwifi_dev_ict_read,
+        TP_PROTO(void *priv, u32 index, u32 value),
+        TP_ARGS(priv, index, value),
+        TP_STRUCT__entry(
+                PRIV_ENTRY
+                __field(u32, index)
+                __field(u32, value)
+        ),
+        TP_fast_assign(
+                PRIV_ASSIGN;
+                __entry->index = index;
+                __entry->value = value;
+        ),
+        TP_printk("read ict[%d] = %#.8x", __entry->index, __entry->value)
+);
+
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM iwlwifi_ucode
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
index 791005d47836..06d5698cd03e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
@@ -1281,6 +1281,8 @@ static irqreturn_t iwl_isr(int irq, void *data)
         if (!trans)
                 return IRQ_NONE;
 
+        trace_iwlwifi_dev_irq(priv(trans));
+
         trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
         spin_lock_irqsave(&trans->shrd->lock, flags);
@@ -1355,6 +1357,7 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
         struct iwl_trans_pcie *trans_pcie;
         u32 inta, inta_mask;
         u32 val = 0;
+        u32 read;
         unsigned long flags;
 
         if (!trans)
@@ -1368,6 +1371,8 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
         if (!trans_pcie->use_ict)
                 return iwl_isr(irq, data);
 
+        trace_iwlwifi_dev_irq(priv(trans));
+
         spin_lock_irqsave(&trans->shrd->lock, flags);
 
         /* Disable (but don't clear!) interrupts here to avoid
@@ -1382,24 +1387,29 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
         /* Ignore interrupt if there's nothing in NIC to service.
          * This may be due to IRQ shared with another device,
          * or due to sporadic interrupts thrown from our NIC. */
-        if (!trans_pcie->ict_tbl[trans_pcie->ict_index]) {
+        read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
+        trace_iwlwifi_dev_ict_read(priv(trans), trans_pcie->ict_index, read);
+        if (!read) {
                 IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
                 goto none;
         }
 
-        /* read all entries that not 0 start with ict_index */
-        while (trans_pcie->ict_tbl[trans_pcie->ict_index]) {
-
-                val |= le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
+        /*
+         * Collect all entries up to the first 0, starting from ict_index;
+         * note we already read at ict_index.
+         */
+        do {
+                val |= read;
                 IWL_DEBUG_ISR(trans, "ICT index %d value 0x%08X\n",
-                                trans_pcie->ict_index,
-                                le32_to_cpu(
-                                  trans_pcie->ict_tbl[trans_pcie->ict_index]));
+                                trans_pcie->ict_index, read);
                 trans_pcie->ict_tbl[trans_pcie->ict_index] = 0;
                 trans_pcie->ict_index =
                         iwl_queue_inc_wrap(trans_pcie->ict_index, ICT_COUNT);
 
-        }
+                read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
+                trace_iwlwifi_dev_ict_read(priv(trans), trans_pcie->ict_index,
+                                           read);
+        } while (read);
 
         /* We should not get this value, just ignore it. */
         if (val == 0xffffffff)
@@ -1426,7 +1436,7 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
         if (likely(inta))
                 tasklet_schedule(&trans_pcie->irq_tasklet);
         else if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) &&
-                        !trans_pcie->inta) {
+                 !trans_pcie->inta) {
                 /* Allow interrupt if was disabled by this handler and
                  * no tasklet was schedules, We should not enable interrupt,
                  * tasklet will enable it.
@@ -1442,7 +1452,7 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
          * only Re-enable if disabled by irq.
          */
         if (test_bit(STATUS_INT_ENABLED, &trans->shrd->status) &&
-                !trans_pcie->inta)
+            !trans_pcie->inta)
                 iwl_enable_interrupts(trans);
 
         spin_unlock_irqrestore(&trans->shrd->lock, flags);