iwlwifi: mvm: fix debugfs restart if fw_restart is disabled

If fw_restart is disabled, using the fw_restart debugfs
file will enable fw_restart and then send the failing
command, but this still frequently fails restart because
it resets fw_restart afterwards and is thus racy.

Fix this by tracking fw_restart separately and allowing
"always restart", "never restart" and "restart N times".

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

diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs.c b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
index 347aa1c..15d52ba 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
@@ -597,20 +597,19 @@ static ssize_t iwl_dbgfs_fw_restart_write(struct file *file,
                                          size_t count, loff_t *ppos)
 {
        struct iwl_mvm *mvm = file->private_data;
-       bool restart_fw = iwlwifi_mod_params.restart_fw;
        int ret;
 
-       iwlwifi_mod_params.restart_fw = true;
-
        mutex_lock(&mvm->mutex);
 
+       /* allow one more restart that we're provoking here */
+       if (mvm->restart_fw >= 0)
+               mvm->restart_fw++;
+
        /* take the return value to make compiler happy - it will fail anyway */
        ret = iwl_mvm_send_cmd_pdu(mvm, REPLY_ERROR, CMD_SYNC, 0, NULL);
 
        mutex_unlock(&mvm->mutex);
 
-       iwlwifi_mod_params.restart_fw = restart_fw;
-
        return count;
 }
 

diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index dda0cd0..5dc5dfd 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -477,6 +477,9 @@ struct iwl_mvm {
         */
        u8 vif_count;
 
+       /* -1 for always, 0 for never, >0 for that many times */
+       s8 restart_fw;
+
        struct led_classdev led;
 
        struct ieee80211_vif *p2p_device_vif;

diff --git a/drivers/net/wireless/iwlwifi/mvm/ops.c b/drivers/net/wireless/iwlwifi/mvm/ops.c
index 70ac726..65e5fb8 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/iwlwifi/mvm/ops.c
@@ -342,6 +342,8 @@ iwl_op_mode_mvm_start(struct iwl_trans *trans, const struct iwl_cfg *cfg,
        mvm->fw = fw;
        mvm->hw = hw;
 
+       mvm->restart_fw = iwlwifi_mod_params.restart_fw ? -1 : 0;
+
        mutex_init(&mvm->mutex);
        spin_lock_init(&mvm->async_handlers_lock);
        INIT_LIST_HEAD(&mvm->time_event_list);
@@ -695,8 +697,7 @@ static void iwl_mvm_nic_restart(struct iwl_mvm *mvm)
                reprobe->dev = mvm->trans->dev;
                INIT_WORK(&reprobe->work, iwl_mvm_reprobe_wk);
                schedule_work(&reprobe->work);
-       } else if (mvm->cur_ucode == IWL_UCODE_REGULAR &&
-                  iwlwifi_mod_params.restart_fw) {
+       } else if (mvm->cur_ucode == IWL_UCODE_REGULAR && mvm->restart_fw) {
                /*
                 * This is a bit racy, but worst case we tell mac80211 about
                 * a stopped/aborted (sched) scan when that was already done
@@ -714,6 +715,8 @@ static void iwl_mvm_nic_restart(struct iwl_mvm *mvm)
                        break;
                }
 
+               if (mvm->restart_fw > 0)
+                       mvm->restart_fw--;
                ieee80211_restart_hw(mvm->hw);
        }
 }
@@ -723,7 +726,7 @@ static void iwl_mvm_nic_error(struct iwl_op_mode *op_mode)
        struct iwl_mvm *mvm = IWL_OP_MODE_GET_MVM(op_mode);
 
        iwl_mvm_dump_nic_error_log(mvm);
-       if (!iwlwifi_mod_params.restart_fw)
+       if (!mvm->restart_fw)
                iwl_mvm_dump_sram(mvm);
 
        iwl_mvm_nic_restart(mvm);