[PATCH 4.19] iwlwifi: mvm: Send LQ command as async when necessary

[PATCH 4.19] iwlwifi: mvm: Send LQ command as async when necessary

[Emmanuel Grumbach]

From: Avraham Stern <avraham.stern@intel.com>

commit 3baf7528d6f832b28622d1ddadd2e47f6c2b5e08 upstream.

The parameter that indicated whether the LQ command should be sent
as sync or async was removed, causing the LQ command to be sent as
sync from interrupt context (e.g. from the RX path). This resulted
in a kernel warning: "scheduling while atomic" and failing to send
the LQ command, which ultimately leads to a queue hang.

Fix it by adding back the required parameter to send the command as
sync only when it is allowed.

Fixes: d94c5a820d10 ("iwlwifi: mvm: open BA session only when sta is authorized")
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
---
 .../net/wireless/intel/iwlwifi/mvm/mac80211.c  |  6 ++++--
 drivers/net/wireless/intel/iwlwifi/mvm/mvm.h   |  2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/rs.c    | 18 ++++++++----------
 drivers/net/wireless/intel/iwlwifi/mvm/rs.h    |  2 +-
 drivers/net/wireless/intel/iwlwifi/mvm/utils.c |  7 +++----
 5 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index afed549f5645..9a764af30f36 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -2938,7 +2938,8 @@ static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
 			iwl_mvm_mac_ctxt_changed(mvm, vif, false, NULL);
 		}
 
-		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt->channel->band);
+		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt->channel->band,
+				     false);
 		ret = iwl_mvm_update_sta(mvm, vif, sta);
 	} else if (old_state == IEEE80211_STA_ASSOC &&
 		   new_state == IEEE80211_STA_AUTHORIZED) {
@@ -2954,7 +2955,8 @@ static int iwl_mvm_mac_sta_state(struct ieee80211_hw *hw,
 		/* enable beacon filtering */
 		WARN_ON(iwl_mvm_enable_beacon_filter(mvm, vif, 0));
 
-		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt->channel->band);
+		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt->channel->band,
+				     true);
 
 		ret = 0;
 	} else if (old_state == IEEE80211_STA_AUTHORIZED &&
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index b3987a0a7018..6b65ad6c9b56 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1685,7 +1685,7 @@ iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 #endif /* CONFIG_IWLWIFI_DEBUGFS */
 
 /* rate scaling */
-int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq, bool init);
+int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq, bool sync);
 void iwl_mvm_update_frame_stats(struct iwl_mvm *mvm, u32 rate, bool agg);
 int rs_pretty_print_rate(char *buf, int bufsz, const u32 rate);
 void rs_update_last_rssi(struct iwl_mvm *mvm,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
index f2830b5693d2..6b9c670fcef8 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
@@ -1280,7 +1280,7 @@ void iwl_mvm_rs_tx_status(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 		       (unsigned long)(lq_sta->last_tx +
 				       (IWL_MVM_RS_IDLE_TIMEOUT * HZ)))) {
 		IWL_DEBUG_RATE(mvm, "Tx idle for too long. reinit rs\n");
-		iwl_mvm_rs_rate_init(mvm, sta, info->band);
+		iwl_mvm_rs_rate_init(mvm, sta, info->band, true);
 		return;
 	}
 	lq_sta->last_tx = jiffies;
@@ -2870,9 +2870,8 @@ void rs_update_last_rssi(struct iwl_mvm *mvm,
 static void rs_initialize_lq(struct iwl_mvm *mvm,
 			     struct ieee80211_sta *sta,
 			     struct iwl_lq_sta *lq_sta,
-			     enum nl80211_band band)
+			     enum nl80211_band band, bool update)
 {
-	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
 	struct iwl_scale_tbl_info *tbl;
 	struct rs_rate *rate;
 	u8 active_tbl = 0;
@@ -2901,8 +2900,7 @@ static void rs_initialize_lq(struct iwl_mvm *mvm,
 	rs_set_expected_tpt_table(lq_sta, tbl);
 	rs_fill_lq_cmd(mvm, sta, lq_sta, rate);
 	/* TODO restore station should remember the lq cmd */
-	iwl_mvm_send_lq_cmd(mvm, &lq_sta->lq,
-			    mvmsta->sta_state < IEEE80211_STA_AUTHORIZED);
+	iwl_mvm_send_lq_cmd(mvm, &lq_sta->lq, !update);
 }
 
 static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta,
@@ -3155,7 +3153,7 @@ void iwl_mvm_update_frame_stats(struct iwl_mvm *mvm, u32 rate, bool agg)
  * Called after adding a new station to initialize rate scaling
  */
 static void rs_drv_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
-			     enum nl80211_band band)
+			     enum nl80211_band band, bool update)
 {
 	int i, j;
 	struct ieee80211_hw *hw = mvm->hw;
@@ -3235,7 +3233,7 @@ static void rs_drv_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 	iwl_mvm_reset_frame_stats(mvm);
 #endif
-	rs_initialize_lq(mvm, sta, lq_sta, band);
+	rs_initialize_lq(mvm, sta, lq_sta, band, update);
 }
 
 static void rs_drv_rate_update(void *mvm_r,
@@ -3255,7 +3253,7 @@ static void rs_drv_rate_update(void *mvm_r,
 	for (tid = 0; tid < IWL_MAX_TID_COUNT; tid++)
 		ieee80211_stop_tx_ba_session(sta, tid);
 
-	iwl_mvm_rs_rate_init(mvm, sta, sband->band);
+	iwl_mvm_rs_rate_init(mvm, sta, sband->band, true);
 }
 
 #ifdef CONFIG_MAC80211_DEBUGFS
@@ -4112,12 +4110,12 @@ static const struct rate_control_ops rs_mvm_ops_drv = {
 };
 
 void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
-			  enum nl80211_band band)
+			  enum nl80211_band band, bool update)
 {
 	if (iwl_mvm_has_tlc_offload(mvm))
 		rs_fw_rate_init(mvm, sta, band);
 	else
-		rs_drv_rate_init(mvm, sta, band);
+		rs_drv_rate_init(mvm, sta, band, update);
 }
 
 int iwl_mvm_rate_control_register(void)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.h b/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
index d2cf484e2b73..8e7f993e2911 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
@@ -420,7 +420,7 @@ struct iwl_lq_sta {
 
 /* Initialize station's rate scaling information after adding station */
 void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
-			  enum nl80211_band band);
+			  enum nl80211_band band, bool init);
 
 /* Notify RS about Tx status */
 void iwl_mvm_rs_tx_status(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
index b002a7afb5f5..6a5349401aa9 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
@@ -900,20 +900,19 @@ int iwl_mvm_disable_txq(struct iwl_mvm *mvm, int queue, int mac80211_queue,
 
 /**
  * iwl_mvm_send_lq_cmd() - Send link quality command
- * @init: This command is sent as part of station initialization right
- *        after station has been added.
+ * @sync: This command can be sent synchronously.
  *
  * The link quality command is sent as the last step of station creation.
  * This is the special case in which init is set and we call a callback in
  * this case to clear the state indicating that station creation is in
  * progress.
  */
-int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq, bool init)
+int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq, bool sync)
 {
 	struct iwl_host_cmd cmd = {
 		.id = LQ_CMD,
 		.len = { sizeof(struct iwl_lq_cmd), },
-		.flags = init ? 0 : CMD_ASYNC,
+		.flags = sync ? 0 : CMD_ASYNC,
 		.data = { lq, },
 	};
 
-- 
2.17.1

Re: [PATCH 4.19] iwlwifi: mvm: Send LQ command as async when necessary

[Luciano Coelho]

Hi Greg,

This patch fixes a few bugs reported in bugzilla, about scheduling
while atomic.  There were at least 4 reports[1], so it seems to be a
common occurrence.

The patch looks large, but it's basically just a new boolean been
passed around in order to decide whether we send a message
synchronously or not.

Is it possible to queue it for 4.19.y?

[1] https://bugzilla.kernel.org/show_bug.cgi?id=200991
    https://bugzilla.kernel.org/show_bug.cgi?id=202219
    https://bugzilla.kernel.org/show_bug.cgi?id=201297
    https://bugzilla.kernel.org/show_bug.cgi?id=201355

--
Cheers,
Luca.


On Tue, 2019-01-22 at 13:50 +0200, Emmanuel Grumbach wrote:
> From: Avraham Stern <avraham.stern@intel.com>
> 
> commit 3baf7528d6f832b28622d1ddadd2e47f6c2b5e08 upstream.
> 
> The parameter that indicated whether the LQ command should be sent
> as sync or async was removed, causing the LQ command to be sent as
> sync from interrupt context (e.g. from the RX path). This resulted
> in a kernel warning: "scheduling while atomic" and failing to send
> the LQ command, which ultimately leads to a queue hang.
> 
> Fix it by adding back the required parameter to send the command as
> sync only when it is allowed.
> 
> Fixes: d94c5a820d10 ("iwlwifi: mvm: open BA session only when sta is
> authorized")
> Signed-off-by: Avraham Stern <avraham.stern@intel.com>
> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
> ---
>  .../net/wireless/intel/iwlwifi/mvm/mac80211.c  |  6 ++++--
>  drivers/net/wireless/intel/iwlwifi/mvm/mvm.h   |  2 +-
>  drivers/net/wireless/intel/iwlwifi/mvm/rs.c    | 18 ++++++++------
> ----
>  drivers/net/wireless/intel/iwlwifi/mvm/rs.h    |  2 +-
>  drivers/net/wireless/intel/iwlwifi/mvm/utils.c |  7 +++----
>  5 files changed, 17 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
> b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
> index afed549f5645..9a764af30f36 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
> @@ -2938,7 +2938,8 @@ static int iwl_mvm_mac_sta_state(struct
> ieee80211_hw *hw,
>  			iwl_mvm_mac_ctxt_changed(mvm, vif, false,
> NULL);
>  		}
>  
> -		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt-
> >channel->band);
> +		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt-
> >channel->band,
> +				     false);
>  		ret = iwl_mvm_update_sta(mvm, vif, sta);
>  	} else if (old_state == IEEE80211_STA_ASSOC &&
>  		   new_state == IEEE80211_STA_AUTHORIZED) {
> @@ -2954,7 +2955,8 @@ static int iwl_mvm_mac_sta_state(struct
> ieee80211_hw *hw,
>  		/* enable beacon filtering */
>  		WARN_ON(iwl_mvm_enable_beacon_filter(mvm, vif, 0));
>  
> -		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt-
> >channel->band);
> +		iwl_mvm_rs_rate_init(mvm, sta, mvmvif->phy_ctxt-
> >channel->band,
> +				     true);
>  
>  		ret = 0;
>  	} else if (old_state == IEEE80211_STA_AUTHORIZED &&
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
> b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
> index b3987a0a7018..6b65ad6c9b56 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
> @@ -1685,7 +1685,7 @@ iwl_mvm_vif_dbgfs_clean(struct iwl_mvm *mvm,
> struct ieee80211_vif *vif)
>  #endif /* CONFIG_IWLWIFI_DEBUGFS */
>  
>  /* rate scaling */
> -int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq,
> bool init);
> +int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq,
> bool sync);
>  void iwl_mvm_update_frame_stats(struct iwl_mvm *mvm, u32 rate, bool
> agg);
>  int rs_pretty_print_rate(char *buf, int bufsz, const u32 rate);
>  void rs_update_last_rssi(struct iwl_mvm *mvm,
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
> b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
> index f2830b5693d2..6b9c670fcef8 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
> @@ -1280,7 +1280,7 @@ void iwl_mvm_rs_tx_status(struct iwl_mvm *mvm,
> struct ieee80211_sta *sta,
>  		       (unsigned long)(lq_sta->last_tx +
>  				       (IWL_MVM_RS_IDLE_TIMEOUT *
> HZ)))) {
>  		IWL_DEBUG_RATE(mvm, "Tx idle for too long. reinit
> rs\n");
> -		iwl_mvm_rs_rate_init(mvm, sta, info->band);
> +		iwl_mvm_rs_rate_init(mvm, sta, info->band, true);
>  		return;
>  	}
>  	lq_sta->last_tx = jiffies;
> @@ -2870,9 +2870,8 @@ void rs_update_last_rssi(struct iwl_mvm *mvm,
>  static void rs_initialize_lq(struct iwl_mvm *mvm,
>  			     struct ieee80211_sta *sta,
>  			     struct iwl_lq_sta *lq_sta,
> -			     enum nl80211_band band)
> +			     enum nl80211_band band, bool update)
>  {
> -	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
>  	struct iwl_scale_tbl_info *tbl;
>  	struct rs_rate *rate;
>  	u8 active_tbl = 0;
> @@ -2901,8 +2900,7 @@ static void rs_initialize_lq(struct iwl_mvm
> *mvm,
>  	rs_set_expected_tpt_table(lq_sta, tbl);
>  	rs_fill_lq_cmd(mvm, sta, lq_sta, rate);
>  	/* TODO restore station should remember the lq cmd */
> -	iwl_mvm_send_lq_cmd(mvm, &lq_sta->lq,
> -			    mvmsta->sta_state <
> IEEE80211_STA_AUTHORIZED);
> +	iwl_mvm_send_lq_cmd(mvm, &lq_sta->lq, !update);
>  }
>  
>  static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta,
> @@ -3155,7 +3153,7 @@ void iwl_mvm_update_frame_stats(struct iwl_mvm
> *mvm, u32 rate, bool agg)
>   * Called after adding a new station to initialize rate scaling
>   */
>  static void rs_drv_rate_init(struct iwl_mvm *mvm, struct
> ieee80211_sta *sta,
> -			     enum nl80211_band band)
> +			     enum nl80211_band band, bool update)
>  {
>  	int i, j;
>  	struct ieee80211_hw *hw = mvm->hw;
> @@ -3235,7 +3233,7 @@ static void rs_drv_rate_init(struct iwl_mvm
> *mvm, struct ieee80211_sta *sta,
>  #ifdef CONFIG_IWLWIFI_DEBUGFS
>  	iwl_mvm_reset_frame_stats(mvm);
>  #endif
> -	rs_initialize_lq(mvm, sta, lq_sta, band);
> +	rs_initialize_lq(mvm, sta, lq_sta, band, update);
>  }
>  
>  static void rs_drv_rate_update(void *mvm_r,
> @@ -3255,7 +3253,7 @@ static void rs_drv_rate_update(void *mvm_r,
>  	for (tid = 0; tid < IWL_MAX_TID_COUNT; tid++)
>  		ieee80211_stop_tx_ba_session(sta, tid);
>  
> -	iwl_mvm_rs_rate_init(mvm, sta, sband->band);
> +	iwl_mvm_rs_rate_init(mvm, sta, sband->band, true);
>  }
>  
>  #ifdef CONFIG_MAC80211_DEBUGFS
> @@ -4112,12 +4110,12 @@ static const struct rate_control_ops
> rs_mvm_ops_drv = {
>  };
>  
>  void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta
> *sta,
> -			  enum nl80211_band band)
> +			  enum nl80211_band band, bool update)
>  {
>  	if (iwl_mvm_has_tlc_offload(mvm))
>  		rs_fw_rate_init(mvm, sta, band);
>  	else
> -		rs_drv_rate_init(mvm, sta, band);
> +		rs_drv_rate_init(mvm, sta, band, update);
>  }
>  
>  int iwl_mvm_rate_control_register(void)
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
> b/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
> index d2cf484e2b73..8e7f993e2911 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.h
> @@ -420,7 +420,7 @@ struct iwl_lq_sta {
>  
>  /* Initialize station's rate scaling information after adding
> station */
>  void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, struct ieee80211_sta
> *sta,
> -			  enum nl80211_band band);
> +			  enum nl80211_band band, bool init);
>  
>  /* Notify RS about Tx status */
>  void iwl_mvm_rs_tx_status(struct iwl_mvm *mvm, struct ieee80211_sta
> *sta,
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
> b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
> index b002a7afb5f5..6a5349401aa9 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c
> @@ -900,20 +900,19 @@ int iwl_mvm_disable_txq(struct iwl_mvm *mvm,
> int queue, int mac80211_queue,
>  
>  /**
>   * iwl_mvm_send_lq_cmd() - Send link quality command
> - * @init: This command is sent as part of station initialization
> right
> - *        after station has been added.
> + * @sync: This command can be sent synchronously.
>   *
>   * The link quality command is sent as the last step of station
> creation.
>   * This is the special case in which init is set and we call a
> callback in
>   * this case to clear the state indicating that station creation is
> in
>   * progress.
>   */
> -int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq,
> bool init)
> +int iwl_mvm_send_lq_cmd(struct iwl_mvm *mvm, struct iwl_lq_cmd *lq,
> bool sync)
>  {
>  	struct iwl_host_cmd cmd = {
>  		.id = LQ_CMD,
>  		.len = { sizeof(struct iwl_lq_cmd), },
> -		.flags = init ? 0 : CMD_ASYNC,
> +		.flags = sync ? 0 : CMD_ASYNC,
>  		.data = { lq, },
>  	};
>  

Re: [PATCH 4.19] iwlwifi: mvm: Send LQ command as async when necessary

[Greg KH]

On Thu, Jan 24, 2019 at 10:47:12AM +0200, Luciano Coelho wrote:
> Hi Greg,
> 
> This patch fixes a few bugs reported in bugzilla, about scheduling
> while atomic.  There were at least 4 reports[1], so it seems to be a
> common occurrence.
> 
> The patch looks large, but it's basically just a new boolean been
> passed around in order to decide whether we send a message
> synchronously or not.
> 
> Is it possible to queue it for 4.19.y?
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=200991
>     https://bugzilla.kernel.org/show_bug.cgi?id=202219
>     https://bugzilla.kernel.org/show_bug.cgi?id=201297
>     https://bugzilla.kernel.org/show_bug.cgi?id=201355

Now queued up, thanks.

Note, apis that add "booleans" to them are horrid, good luck maintaining
that mess :(

greg k-h

Re: [PATCH 4.19] iwlwifi: mvm: Send LQ command as async when necessary

[Luciano Coelho]

On Thu, 2019-01-24 at 18:50 +0100, Greg KH wrote:
> On Thu, Jan 24, 2019 at 10:47:12AM +0200, Luciano Coelho wrote:
> > Hi Greg,
> > 
> > This patch fixes a few bugs reported in bugzilla, about scheduling
> > while atomic.  There were at least 4 reports[1], so it seems to be
> > a
> > common occurrence.
> > 
> > The patch looks large, but it's basically just a new boolean been
> > passed around in order to decide whether we send a message
> > synchronously or not.
> > 
> > Is it possible to queue it for 4.19.y?
> > 
> > [1] https://bugzilla.kernel.org/show_bug.cgi?id=200991
> >     https://bugzilla.kernel.org/show_bug.cgi?id=202219
> >     https://bugzilla.kernel.org/show_bug.cgi?id=201297
> >     https://bugzilla.kernel.org/show_bug.cgi?id=201355
> 
> Now queued up, thanks.

Thanks, Greg!


> Note, apis that add "booleans" to them are horrid, good luck
> maintaining that mess :(

Yeah, you're right.  This patch demonstrates that, the boolean needs to
be passed from and to everywhere.  We should probably just split that
function in two.  Thanks for the comment.

--
Cheers,
Luca.