diff mbox series

[14/15] iwlwifi: mvm: Send LQ command as async when necessary

Message ID 20180821063657.30071-15-luca@coelho.fi (mailing list archive)
State Accepted
Delegated to: Luca Coelho
Headers show
Series iwlwifi: updates intended for v4.20 2018-08-21 | expand

Commit Message

Luca Coelho Aug. 21, 2018, 6:36 a.m. UTC
From: Avraham Stern <avraham.stern@intel.com>

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>
---
 .../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(-)

Comments

Tee Hao Wei Sept. 6, 2018, 8:22 a.m. UTC | #1
Hi,

On 21/8/18 2:36 PM, Luca Coelho wrote:
> From: Avraham Stern <avraham.stern@intel.com>
> 
> 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>

I'm not sure whether you guys normally send fixes to stable, but this
really should go to stable. I run into this bug as often as a few times
an hour and sometimes it leads to IRQs from other devices being dropped
(e.g. touchpad, in turn causing the driver to timeout and quit, and the
touchpad dies).

Thanks.
Luca Coelho Sept. 6, 2018, 8:44 a.m. UTC | #2
On Thu, 2018-09-06 at 16:22 +0800, Hao Wei Tee wrote:
> Hi,

Hi Hao Wei,


> On 21/8/18 2:36 PM, Luca Coelho wrote:
> > From: Avraham Stern <avraham.stern@intel.com>
> > 
> > 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>
> 
> I'm not sure whether you guys normally send fixes to stable, but this
> really should go to stable. I run into this bug as often as a few times
> an hour and sometimes it leads to IRQs from other devices being dropped
> (e.g. touchpad, in turn causing the driver to timeout and quit, and the
> touchpad dies).

We do send things for stable and the "Fixes" tag included in this patch
will cause it to be automatically considered for the stable releases
that contain the commit it points to.  So we should be fine here.

If you notice that, for some reason, this doesn't end up applied in the
specific stable kernel you need it on, please let us know and we'll
check it out.  Also note that anyone can suggest any patch to stable
releases, there's a process[1] in place for that.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst

Thanks for your contribution!

--
Cheers,
Luca.
diff mbox series

Patch

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index c0c3ff6a0e6a..c95c1f3c1fb4 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -2949,7 +2949,8 @@  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) {
@@ -2965,7 +2966,8 @@  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 762abfc42b62..98189f2f1e65 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -1708,7 +1708,7 @@  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 30cfd7d50bc9..d3e389a99a8a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c
@@ -1276,7 +1276,7 @@  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;
@@ -2859,9 +2859,8 @@  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;
@@ -2890,8 +2889,7 @@  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,
@@ -3144,7 +3142,7 @@  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;
@@ -3224,7 +3222,7 @@  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,
@@ -3244,7 +3242,7 @@  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
@@ -4098,12 +4096,12 @@  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, },
 	};