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

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
index 36196e07b1a04597d61b5cadca7f7d0d927fc432..5cec467b995bb665f340d95b6aa33f10436ab0e0 100644 (file)
--- 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)

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.h b/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
index 2e2d60a586925d8a03714ab5919344da50ae4438..0fd009e6d6857f5939e73356c9f73a46001fe4d5 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
@@ -89,4 +89,7 @@ void iwl_drv_stop(struct iwl_drv *drv);
 #define IWL_EXPORT_SYMBOL(sym)
 #endif
 
+/* max retry for init flow */
+#define IWL_MAX_INIT_RETRY 2
+
 #endif /* __iwl_drv_h__ */

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 9fb9c7dad314f1bcbbf6e4f67645befdb3d31d08..897e3b91ddb2fec9e3d2f85842fbcc85f44281ca 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -16,6 +16,7 @@
 #include <net/ieee80211_radiotap.h>
 #include <net/tcp.h>
 
+#include "iwl-drv.h"
 #include "iwl-op-mode.h"
 #include "iwl-io.h"
 #include "mvm.h"
@@ -1117,9 +1118,30 @@ static int iwl_mvm_mac_start(struct ieee80211_hw *hw)
 {
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        int ret;
+       int retry, max_retry = 0;
 
        mutex_lock(&mvm->mutex);
-       ret = __iwl_mvm_mac_start(mvm);
+
+       /* we are starting the mac not in error flow, and restart is enabled */
+       if (!test_bit(IWL_MVM_STATUS_HW_RESTART_REQUESTED, &mvm->status) &&
+           iwlwifi_mod_params.fw_restart) {
+               max_retry = IWL_MAX_INIT_RETRY;
+               /*
+                * This will prevent mac80211 recovery flows to trigger during
+                * init failures
+                */
+               set_bit(IWL_MVM_STATUS_STARTING, &mvm->status);
+       }
+
+       for (retry = 0; retry <= max_retry; retry++) {
+               ret = __iwl_mvm_mac_start(mvm);
+               if (!ret)
+                       break;
+
+               IWL_ERR(mvm, "mac start retry %d\n", retry);
+       }
+       clear_bit(IWL_MVM_STATUS_STARTING, &mvm->status);
+
        mutex_unlock(&mvm->mutex);
 
        return ret;

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 2b1dcd60e00f65598d77712b042493247b4a2b91..a72d85086fe331cb256a2e88c88293a5e4b55bf0 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1123,6 +1123,8 @@ struct iwl_mvm {
  * @IWL_MVM_STATUS_FIRMWARE_RUNNING: firmware is running
  * @IWL_MVM_STATUS_NEED_FLUSH_P2P: need to flush P2P bcast STA
  * @IWL_MVM_STATUS_IN_D3: in D3 (or at least about to go into it)
+ * @IWL_MVM_STATUS_STARTING: starting mac,
+ *     used to disable restart flow while in STARTING state
  */
 enum iwl_mvm_status {
        IWL_MVM_STATUS_HW_RFKILL,
@@ -1134,6 +1136,7 @@ enum iwl_mvm_status {
        IWL_MVM_STATUS_FIRMWARE_RUNNING,
        IWL_MVM_STATUS_NEED_FLUSH_P2P,
        IWL_MVM_STATUS_IN_D3,
+       IWL_MVM_STATUS_STARTING,
 };
 
 /* Keep track of completed init configuration */

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index 232ad531d612a2d2b4e85fc7a8558919b119ad8d..ce7160670aa717ed0e88ee27976762adab3d9676 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1600,6 +1600,9 @@ void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error)
         */
        if (!mvm->fw_restart && fw_error) {
                iwl_fw_error_collect(&mvm->fwrt, false);
+       } else if (test_bit(IWL_MVM_STATUS_STARTING,
+                           &mvm->status)) {
+               IWL_ERR(mvm, "Starting mac, retry will be triggered anyway\n");
        } else if (test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
                struct iwl_mvm_reprobe *reprobe;