iwlwifi: pcie: don't disable interrupts for reg_lock

The only thing we do touching the device in hard interrupt context
is, at most, writing an interrupt ACK register, which isn't racing
in with anything protected by the reg_lock.

Thus, avoid disabling interrupts here for potentially long periods
of time, particularly long periods have been observed with dumping
of firmware memory (leading to lockup warnings on some devices.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210210135352.da916ab91298.I064c3e7823b616647293ed97da98edefb9ce9435@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 16f5757b1260487be7006bb6caf194abdf1848cb..a73f2c54d4468282f82b33bd4a6fe067cd98373f 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -1972,7 +1972,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
        int ret;
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
-       spin_lock_irqsave(&trans_pcie->reg_lock, *flags);
+       spin_lock_bh(&trans_pcie->reg_lock);
 
        if (trans_pcie->cmd_hold_nic_awake)
                goto out;
@@ -2057,7 +2057,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
                }
 
 err:
-               spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
+               spin_unlock_bh(&trans_pcie->reg_lock);
                return false;
        }
 
@@ -2095,7 +2095,7 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
         * scheduled on different CPUs (after we drop reg_lock).
         */
 out:
-       spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
+       spin_unlock_bh(&trans_pcie->reg_lock);
 }
 
 static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr,
@@ -2296,11 +2296,10 @@ static void iwl_trans_pcie_set_bits_mask(struct iwl_trans *trans, u32 reg,
                                         u32 mask, u32 value)
 {
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
-       unsigned long flags;
 
-       spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+       spin_lock_bh(&trans_pcie->reg_lock);
        __iwl_trans_pcie_set_bits_mask(trans, reg, mask, value);
-       spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+       spin_unlock_bh(&trans_pcie->reg_lock);
 }
 
 static const char *get_csr_string(int cmd)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
index 1099df7bc26f07ac37f5f6b2f9c71b9f0b9cf869..4456abb9a0742da020e2a9fcfc3638f4118e9f6d 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -31,7 +31,6 @@ int iwl_pcie_gen2_enqueue_hcmd(struct iwl_trans *trans,
        struct iwl_txq *txq = trans->txqs.txq[trans->txqs.cmd.q_id];
        struct iwl_device_cmd *out_cmd;
        struct iwl_cmd_meta *out_meta;
-       unsigned long flags;
        void *dup_buf = NULL;
        dma_addr_t phys_addr;
        int i, cmd_pos, idx;
@@ -244,11 +243,11 @@ int iwl_pcie_gen2_enqueue_hcmd(struct iwl_trans *trans,
        if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)
                mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);
 
-       spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+       spin_lock(&trans_pcie->reg_lock);
        /* Increment and update queue's write index */
        txq->write_ptr = iwl_txq_inc_wrap(trans, txq->write_ptr);
        iwl_txq_inc_wr_ptr(trans, txq);
-       spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+       spin_unlock(&trans_pcie->reg_lock);
 
 out:
        spin_unlock_bh(&txq->lock);

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
index 2e9d4113a9f1994c8038ebcb547d125ad7e75d47..e8acbfbf3ddc094aa66b2ea008c568a3d3a66ada 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -223,12 +223,10 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id)
                txq->read_ptr = iwl_txq_inc_wrap(trans, txq->read_ptr);
 
                if (txq->read_ptr == txq->write_ptr) {
-                       unsigned long flags;
-
-                       spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+                       spin_lock(&trans_pcie->reg_lock);
                        if (txq_id == trans->txqs.cmd.q_id)
                                iwl_pcie_clear_cmd_in_flight(trans);
-                       spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+                       spin_unlock(&trans_pcie->reg_lock);
                }
        }
 
@@ -679,7 +677,6 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)
 {
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *txq = trans->txqs.txq[txq_id];
-       unsigned long flags;
        int nfreed = 0;
        u16 r;
 
@@ -710,9 +707,10 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)
        }
 
        if (txq->read_ptr == txq->write_ptr) {
-               spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+               /* BHs are also disabled due to txq->lock */
+               spin_lock(&trans_pcie->reg_lock);
                iwl_pcie_clear_cmd_in_flight(trans);
-               spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+               spin_unlock(&trans_pcie->reg_lock);
        }
 
        iwl_txq_progress(txq);
@@ -921,7 +919,6 @@ int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
        struct iwl_txq *txq = trans->txqs.txq[trans->txqs.cmd.q_id];
        struct iwl_device_cmd *out_cmd;
        struct iwl_cmd_meta *out_meta;
-       unsigned long flags;
        void *dup_buf = NULL;
        dma_addr_t phys_addr;
        int idx;
@@ -1164,20 +1161,19 @@ int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
        if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)
                mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);
 
-       spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+       spin_lock(&trans_pcie->reg_lock);
        ret = iwl_pcie_set_cmd_in_flight(trans, cmd);
        if (ret < 0) {
                idx = ret;
-               spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
-               goto out;
+               goto unlock_reg;
        }
 
        /* Increment and update queue's write index */
        txq->write_ptr = iwl_txq_inc_wrap(trans, txq->write_ptr);
        iwl_pcie_txq_inc_wr_ptr(trans, txq);
 
-       spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
-
+ unlock_reg:
+       spin_unlock(&trans_pcie->reg_lock);
  out:
        spin_unlock_bh(&txq->lock);
  free_dup_buf: