[PATCH 5.10 127/130] iwlwifi: mvm: retry init flow if failed

Greg Kroah-Hartman
2021-12-06T15:34:32Z

From: Mordechay Goodstein <mordechay.goodstein@intel.com>

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>
---
drivers/net/wireless/intel/iwlwifi/iwl-drv.c | 22 +++++++++++++-------
drivers/net/wireless/intel/iwlwifi/iwl-drv.h | 3 ++
drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 24 +++++++++++++++++++++-
drivers/net/wireless/intel/iwlwifi/mvm/mvm.h | 3 ++
drivers/net/wireless/intel/iwlwifi/mvm/ops.c | 3 ++
5 files changed, 47 insertions(+), 8 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
@@ -1303,23 +1303,31 @@ _iwl_op_mode_start(struct iwl_drv *drv,
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)
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.h
@@ -144,4 +144,7 @@ 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__ */
--- 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"
@@ -1163,9 +1164,30 @@ static int iwl_mvm_mac_start(struct ieee
{
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;
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1162,6 +1162,8 @@ 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,
@@ -1173,6 +1175,7 @@ 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 */
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1295,6 +1295,9 @@ void iwl_mvm_nic_restart(struct iwl_mvm
*/
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;