iwlwifi: mvm: enable watchdog on Tx queues for mvm

This watchdog allows to monitor the transmit queues. When a
queue doesn't progress for a too long time, a timer fires
and then, debug data can be collected.
This watchdog has never been enabled on dvm controlled
devices, so don't enable it there.
In order to have it running on mvm controlled devices, we
need to fix a small issue in the transport layer: mvm
controlled devices use the shadow registers optimization.
In this case, the watchdog wasn't running at all, even if
enabled by the module parameter. Fix that on the way.

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

6 files changed, 10 insertions, 16 deletions

diff --git a/drivers/net/wireless/iwlwifi/dvm/main.c b/drivers/net/wireless/iwlwifi/dvm/main.c
index de43dd7e170a..a21400cd84ac 100644
--- a/drivers/net/wireless/iwlwifi/dvm/main.c
+++ b/drivers/net/wireless/iwlwifi/dvm/main.c
@@ -1228,11 +1228,7 @@ static struct iwl_op_mode *iwl_op_mode_dvm_start(struct iwl_trans *trans,
         trans_cfg.no_reclaim_cmds = no_reclaim_cmds;
         trans_cfg.n_no_reclaim_cmds = ARRAY_SIZE(no_reclaim_cmds);
         trans_cfg.rx_buf_size_8k = iwlwifi_mod_params.amsdu_size_8K;
-        if (!iwlwifi_mod_params.wd_disable)
-                trans_cfg.queue_watchdog_timeout =
-                        priv->cfg->base_params->wd_timeout;
-        else
-                trans_cfg.queue_watchdog_timeout = IWL_WATCHDOG_DISABLED;
+        trans_cfg.queue_watchdog_timeout = IWL_WATCHDOG_DISABLED;
         trans_cfg.command_names = iwl_dvm_cmd_strings;
         trans_cfg.cmd_fifo = IWLAGN_CMD_FIFO_NUM;
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-drv.c b/drivers/net/wireless/iwlwifi/iwl-drv.c
index e7c0df6db6ee..996e7f16adf9 100644
--- a/drivers/net/wireless/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/iwlwifi/iwl-drv.c
@@ -1367,7 +1367,6 @@ struct iwl_mod_params iwlwifi_mod_params = {
         .restart_fw = true,
         .bt_coex_active = true,
         .power_level = IWL_POWER_INDEX_1,
-        .wd_disable = true,
         .d0i3_disable = true,
 #ifndef CONFIG_IWLWIFI_UAPSD
         .uapsd_disable = true,
@@ -1478,10 +1477,6 @@ module_param_named(antenna_coupling, iwlwifi_mod_params.ant_coupling,
 MODULE_PARM_DESC(antenna_coupling,
                  "specify antenna coupling in dB (default: 0 dB)");
 
-module_param_named(wd_disable, iwlwifi_mod_params.wd_disable, int, S_IRUGO);
-MODULE_PARM_DESC(wd_disable,
-                "Disable stuck queue watchdog timer 0=system default, 1=disable (default: 1)");
-
 module_param_named(nvm_file, iwlwifi_mod_params.nvm_file, charp, S_IRUGO);
 MODULE_PARM_DESC(nvm_file, "NVM file name");
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-modparams.h b/drivers/net/wireless/iwlwifi/iwl-modparams.h
index 2a8cf4b2445c..e8eabd21ccfe 100644
--- a/drivers/net/wireless/iwlwifi/iwl-modparams.h
+++ b/drivers/net/wireless/iwlwifi/iwl-modparams.h
@@ -96,7 +96,6 @@ enum iwl_disable_11n {
  *      use IWL_[DIS,EN]ABLE_HT_* constants
  * @amsdu_size_8K: enable 8K amsdu size, default = 0
  * @restart_fw: restart firmware, default = 1
- * @wd_disable: disable stuck queue check, default = 1
  * @bt_coex_active: enable bt coex, default = true
  * @led_mode: system default, default = 0
  * @power_save: enable power save, default = false
@@ -111,7 +110,6 @@ struct iwl_mod_params {
         unsigned int disable_11n;
         int amsdu_size_8K;
         bool restart_fw;
-        int  wd_disable;
         bool bt_coex_active;
         int led_mode;
         bool power_save;
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index ed097268a1bc..4a7620cb5775 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -119,11 +119,13 @@ extern const struct ieee80211_ops iwl_mvm_hw_ops;
  *      We will register to mac80211 to have testmode working. The NIC must not
  *      be up'ed after the INIT fw asserted. This is useful to be able to use
  *      proprietary tools over testmode to debug the INIT fw.
+ * @tfd_q_hang_detect: enabled the detection of hung transmit queues
  * @power_scheme: CAM(Continuous Active Mode)-1, BPS(Balanced Power
  *      Save)-2(default), LP(Low Power)-3
  */
 struct iwl_mvm_mod_params {
         bool init_dbg;
+        bool tfd_q_hang_detect;
         int power_scheme;
 };
 extern struct iwl_mvm_mod_params iwlmvm_mod_params;
diff --git a/drivers/net/wireless/iwlwifi/mvm/ops.c b/drivers/net/wireless/iwlwifi/mvm/ops.c
index b1dea6800b3b..f801824197e1 100644
--- a/drivers/net/wireless/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/iwlwifi/mvm/ops.c
@@ -93,6 +93,7 @@ static const struct iwl_op_mode_ops iwl_mvm_ops;
 
 struct iwl_mvm_mod_params iwlmvm_mod_params = {
         .power_scheme = IWL_POWER_SCHEME_BPS,
+        .tfd_q_hang_detect = true
         /* rest of fields are 0 by default */
 };
 
@@ -102,6 +103,10 @@ MODULE_PARM_DESC(init_dbg,
 module_param_named(power_scheme, iwlmvm_mod_params.power_scheme, int, S_IRUGO);
 MODULE_PARM_DESC(power_scheme,
                  "power management scheme: 1-active, 2-balanced, 3-low power, default: 2");
+module_param_named(tfd_q_hang_detect, iwlmvm_mod_params.tfd_q_hang_detect,
+                   bool, S_IRUGO);
+MODULE_PARM_DESC(tfd_q_hang_detect,
+                 "TFD queues hang detection (default: true");
 
 /*
  * module init and exit functions
@@ -473,10 +478,8 @@ iwl_op_mode_mvm_start(struct iwl_trans *trans, const struct iwl_cfg *cfg,
         if (mvm->fw->ucode_capa.flags & IWL_UCODE_TLV_FLAGS_DW_BC_TABLE)
                 trans_cfg.bc_table_dword = true;
 
-        if (!iwlwifi_mod_params.wd_disable)
+        if (iwlmvm_mod_params.tfd_q_hang_detect)
                 trans_cfg.queue_watchdog_timeout = cfg->base_params->wd_timeout;
-        else
-                trans_cfg.queue_watchdog_timeout = IWL_WATCHDOG_DISABLED;
 
         trans_cfg.command_names = iwl_mvm_cmd_strings;
 
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c
index 59aefa43ea85..bb9dd3ecbcf5 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -1849,7 +1849,7 @@ int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 
         /* start timer if queue currently empty */
         if (q->read_ptr == q->write_ptr) {
-                if (txq->need_update && trans_pcie->wd_timeout)
+                if (trans_pcie->wd_timeout)
                         mod_timer(&txq->stuck_timer,
                                   jiffies + trans_pcie->wd_timeout);
                 IWL_DEBUG_RPM(trans, "Q: %d first tx - take ref\n", q->id);