iwlwifi: mvm: retry init flow if failed

BugLink: https://bugs.launchpad.net/bugs/1956381
commit 5283dd677e52af9db6fe6ad11b2f12220d519d0c upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
index 7c4a95ebe9e35a90fb04ddc3f53e81450565b095..68b7416b355d0aafc4a14c37ea7f0afb399ad3f1 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
@@ -1276,23 +1276,31 @@ _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 2be30af7bdc30861bea107a2e941dc29ab2c57ec..9663db12b6f32e28c1c21625ca1468cd6492fb21 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
@@ -145,4 +145,7 @@ 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 081cbc9ec736824bf2b411fb80bd168523b176cc..c942255aa1dbc4cd1f271660e2b5b40101e2f5b7 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -71,6 +71,7 @@
 #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"
@@ -1129,9 +1130,30 @@ 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 5f1ecbb6fb71d7c2ebbda0bdd133fb3fc978b7d9..b06a9da753ff784c5ecd07ee60b4d1205c1c2224 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1167,6 +1167,8 @@ struct iwl_mvm {
  * @IWL_MVM_STATUS_ROC_AUX_RUNNING: AUX remain-on-channel is running
  * @IWL_MVM_STATUS_FIRMWARE_RUNNING: firmware is running
  * @IWL_MVM_STATUS_NEED_FLUSH_P2P: need to flush P2P bcast STA
+ * @IWL_MVM_STATUS_STARTING: starting mac,
+ *     used to disable restart flow while in STARTING state
  */
 enum iwl_mvm_status {
        IWL_MVM_STATUS_HW_RFKILL,
@@ -1177,6 +1179,7 @@ enum iwl_mvm_status {
        IWL_MVM_STATUS_ROC_AUX_RUNNING,
        IWL_MVM_STATUS_FIRMWARE_RUNNING,
        IWL_MVM_STATUS_NEED_FLUSH_P2P,
+       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 698871ef819b5fa7b3d96d90dc5639658b9cf9cc..2e65cfef686812568f6dba6ecf7b0aa0c379e153 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1288,6 +1288,9 @@ void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error)
         */
        if (!mvm->fw_restart && fw_error) {
                iwl_fw_error_collect(&mvm->fwrt);
+       } 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;