iwlwifi: protect use_ict with irq_lock

This variable was accessed without taking the lock.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 14 insertions, 16 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c
index d6860c070c16..be143eb4aa4f 100644
--- a/drivers/net/wireless/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/rx.c
@@ -867,24 +867,23 @@ void iwl_disable_ict(struct iwl_trans *trans)
         spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
 }
 
+/* legacy (non-ICT) ISR. Assumes that trans_pcie->irq_lock is held */
 static irqreturn_t iwl_isr(int irq, void *data)
 {
         struct iwl_trans *trans = data;
-        struct iwl_trans_pcie *trans_pcie;
+        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
         u32 inta, inta_mask;
-        unsigned long flags;
 #ifdef CONFIG_IWLWIFI_DEBUG
         u32 inta_fh;
 #endif
+
+        lockdep_assert_held(&trans_pcie->irq_lock);
+
         if (!trans)
                 return IRQ_NONE;
 
         trace_iwlwifi_dev_irq(trans->dev);
 
-        trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
-
-        spin_lock_irqsave(&trans_pcie->irq_lock, flags);
-
         /* Disable (but don't clear!) interrupts here to avoid
          *    back-to-back ISRs and sporadic interrupts from our NIC.
          * If we have something to service, the tasklet will re-enable ints.
@@ -907,7 +906,7 @@ static irqreturn_t iwl_isr(int irq, void *data)
                 /* Hardware disappeared. It might have already raised
                  * an interrupt */
                 IWL_WARN(trans, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
-                goto unplugged;
+                return IRQ_HANDLED;
         }
 
 #ifdef CONFIG_IWLWIFI_DEBUG
@@ -926,18 +925,13 @@ static irqreturn_t iwl_isr(int irq, void *data)
                  !trans_pcie->inta)
                 iwl_enable_interrupts(trans);
 
- unplugged:
-        spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
-        return IRQ_HANDLED;
-
- none:
+none:
         /* re-enable interrupts here since we don't have anything to service. */
         /* only Re-enable if disabled by irq  and no schedules tasklet. */
         if (test_bit(STATUS_INT_ENABLED, &trans_pcie->status) &&
             !trans_pcie->inta)
                 iwl_enable_interrupts(trans);
 
-        spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
         return IRQ_NONE;
 }
 
@@ -963,15 +957,19 @@ irqreturn_t iwl_isr_ict(int irq, void *data)
 
         trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
+        spin_lock_irqsave(&trans_pcie->irq_lock, flags);
+
         /* dram interrupt table not set yet,
          * use legacy interrupt.
          */
-        if (!trans_pcie->use_ict)
-                return iwl_isr(irq, data);
+        if (unlikely(!trans_pcie->use_ict)) {
+                irqreturn_t ret = iwl_isr(irq, data);
+                spin_unlock_irqrestore(&trans_pcie->irq_lock, flags);
+                return ret;
+        }
 
         trace_iwlwifi_dev_irq(trans->dev);
 
-        spin_lock_irqsave(&trans_pcie->irq_lock, flags);
 
         /* Disable (but don't clear!) interrupts here to avoid
          * back-to-back ISRs and sporadic interrupts from our NIC.