iwlwifi: use threaded interrupt handler

With new transports coming up, move to threaded
interrupt handling now. This has the advantage
that we can use the same locking scheme with all
different transports we may need to implement.

Note that the TX path obviously still runs in a
tasklet, so some spin_lock() calls need to change
to spin_lock_bh() calls to properly lock out the
TX path.

In my test on a Calpella platform this has no
impact on throughput or latency.

Also add lockdep annotations to avoid lockups due
to catch sending synchronous commands or using
locks that connect with them from the irq thread.

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

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 56d4f72500bc..17bedc50e753 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -760,7 +760,6 @@ void iwl_trans_pcie_free(struct iwl_trans *trans)
         struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
         synchronize_irq(trans_pcie->pci_dev->irq);
-        tasklet_kill(&trans_pcie->irq_tasklet);
 
         iwl_pcie_tx_free(trans);
         iwl_pcie_rx_free(trans);
@@ -1480,6 +1479,7 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 
         trans->ops = &trans_ops_pcie;
         trans->cfg = cfg;
+        trans_lockdep_init(trans);
         trans_pcie->trans = trans;
         spin_lock_init(&trans_pcie->irq_lock);
         spin_lock_init(&trans_pcie->reg_lock);
@@ -1567,15 +1567,12 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 
         trans_pcie->inta_mask = CSR_INI_SET_MASK;
 
-        tasklet_init(&trans_pcie->irq_tasklet, (void (*)(unsigned long))
-                     iwl_pcie_tasklet, (unsigned long)trans);
-
         if (iwl_pcie_alloc_ict(trans))
                 goto out_free_cmd_pool;
 
-        err = request_irq(pdev->irq, iwl_pcie_isr_ict,
-                          IRQF_SHARED, DRV_NAME, trans);
-        if (err) {
+        if (request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
+                                 iwl_pcie_irq_handler,
+                                 IRQF_SHARED, DRV_NAME, trans)) {
                 IWL_ERR(trans, "Error allocating IRQ %d\n", pdev->irq);
                 goto out_free_ict;
         }