iwlwifi: mvm: retry init flow if failed

In some very rare cases the init flow may fail.  In many cases, this is
recoverable, so we can retry.  Implement a loop to retry two more times
after the first attempt failed.

This can happen in two different situations, namely during probe and
during mac80211 start.  For the first case, a simple loop is enough.
For the second case, we need to add a flag to prevent mac80211 from
trying to restart it as well, leaving full control with the driver.

Cc: <stable@vger.kernel.org>
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20211110150132.57514296ecab.I52a0411774b700bdc7dedb124d8b59bf99456eb2@changeid

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
index 36196e07b1a0..5cec467b995b 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
@@ -1313,23 +1313,31 @@ _iwl_op_mode_start(struct iwl_drv *drv, struct iwlwifi_opmode_table *op)
 	const struct iwl_op_mode_ops *ops = op->ops;
 	struct dentry *dbgfs_dir = NULL;
 	struct iwl_op_mode *op_mode = NULL;
+	int retry, max_retry = !!iwlwifi_mod_params.fw_restart * IWL_MAX_INIT_RETRY;
+
+	for (retry = 0; retry <= max_retry; retry++) {
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
-	drv->dbgfs_op_mode = debugfs_create_dir(op->name,
-						drv->dbgfs_drv);
-	dbgfs_dir = drv->dbgfs_op_mode;
+		drv->dbgfs_op_mode = debugfs_create_dir(op->name,
+							drv->dbgfs_drv);
+		dbgfs_dir = drv->dbgfs_op_mode;
 #endif
 
-	op_mode = ops->start(drv->trans, drv->trans->cfg, &drv->fw, dbgfs_dir);
+		op_mode = ops->start(drv->trans, drv->trans->cfg,
+				     &drv->fw, dbgfs_dir);
+
+		if (op_mode)
+			return op_mode;
+
+		IWL_ERR(drv, "retry init count %d\n", retry);
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
-	if (!op_mode) {
 		debugfs_remove_recursive(drv->dbgfs_op_mode);
 		drv->dbgfs_op_mode = NULL;
-	}
 #endif
+	}
 
-	return op_mode;
+	return NULL;
 }
 
 static void _iwl_op_mode_stop(struct iwl_drv *drv)