ath6kl: Add support to detect fw error through heart beat

This patch adds support to detect fw error condition by sending
periodic message (heart beat challenge) to firmware. Upon reception
of the message, fw would send a response event to driver. When
there are no reponses from fw for about 5 cmd driver would
trigger the recovery logic assuming that fw has gone into an
error state.

Capable fw will advertise this capability through
ATH6KL_FW_CAPABILITY_HEART_BEAT_POLL bit. This feature
is disabled by default, can be enabled through a modparam
(heart_beat_poll). This modparam also confiures the polling
interval in msecs.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 87 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/recovery.c b/drivers/net/wireless/ath/ath6kl/recovery.c
index c225fc4d3d56..4e3f205bb8a0 100644
--- a/drivers/net/wireless/ath/ath6kl/recovery.c
+++ b/drivers/net/wireless/ath/ath6kl/recovery.c
@@ -23,7 +23,18 @@ static void ath6kl_recovery_work(struct work_struct *work)
 	struct ath6kl *ar = container_of(work, struct ath6kl,
 					 fw_recovery.recovery_work);
 
+	ar->state = ATH6KL_STATE_RECOVERY;
+
+	del_timer_sync(&ar->fw_recovery.hb_timer);
+
 	ath6kl_init_hw_restart(ar);
+
+	ar->state = ATH6KL_STATE_ON;
+	ar->fw_recovery.err_reason = 0;
+
+	if (ar->fw_recovery.enable)
+		mod_timer(&ar->fw_recovery.hb_timer, jiffies +
+			  msecs_to_jiffies(ar->fw_recovery.hb_poll));
 }
 
 void ath6kl_recovery_err_notify(struct ath6kl *ar, enum ath6kl_fw_err reason)
@@ -37,18 +48,72 @@ void ath6kl_recovery_err_notify(struct ath6kl *ar, enum ath6kl_fw_err reason)
 		queue_work(ar->ath6kl_wq, &ar->fw_recovery.recovery_work);
 }
 
+void ath6kl_recovery_hb_event(struct ath6kl *ar, u32 cookie)
+{
+	if (cookie == ar->fw_recovery.seq_num)
+		ar->fw_recovery.hb_pending = false;
+}
+
+static void ath6kl_recovery_hb_timer(unsigned long data)
+{
+	struct ath6kl *ar = (struct ath6kl *) data;
+	int err;
+
+	if (!ar->fw_recovery.enable)
+		return;
+
+	if (ar->fw_recovery.hb_pending)
+		ar->fw_recovery.hb_misscnt++;
+	else
+		ar->fw_recovery.hb_misscnt = 0;
+
+	if (ar->fw_recovery.hb_misscnt > ATH6KL_HB_RESP_MISS_THRES) {
+		ar->fw_recovery.hb_misscnt = 0;
+		ar->fw_recovery.seq_num = 0;
+		ar->fw_recovery.hb_pending = false;
+		ath6kl_recovery_err_notify(ar, ATH6KL_FW_HB_RESP_FAILURE);
+		return;
+	}
+
+	ar->fw_recovery.seq_num++;
+	ar->fw_recovery.hb_pending = true;
+
+	err = ath6kl_wmi_get_challenge_resp_cmd(ar->wmi,
+						ar->fw_recovery.seq_num, 0);
+	if (err)
+		ath6kl_warn("Failed to send hb challenge request, err:%d\n",
+			    err);
+
+	if ((ar->state == ATH6KL_STATE_RECOVERY) || !ar->fw_recovery.enable)
+		return;
+
+	mod_timer(&ar->fw_recovery.hb_timer, jiffies +
+		  msecs_to_jiffies(ar->fw_recovery.hb_poll));
+}
+
 void ath6kl_recovery_init(struct ath6kl *ar)
 {
 	struct ath6kl_fw_recovery *recovery = &ar->fw_recovery;
 
 	recovery->enable = true;
 	INIT_WORK(&recovery->recovery_work, ath6kl_recovery_work);
+	recovery->seq_num = 0;
+	recovery->hb_misscnt = 0;
+	ar->fw_recovery.hb_pending = false;
+	ar->fw_recovery.hb_timer.function = ath6kl_recovery_hb_timer;
+	ar->fw_recovery.hb_timer.data = (unsigned long) ar;
+	init_timer_deferrable(&ar->fw_recovery.hb_timer);
+
+	if (ar->fw_recovery.hb_poll)
+		mod_timer(&ar->fw_recovery.hb_timer, jiffies +
+			  msecs_to_jiffies(ar->fw_recovery.hb_poll));
 }
 
 void ath6kl_recovery_cleanup(struct ath6kl *ar)
 {
 	ar->fw_recovery.enable = false;
 
+	del_timer_sync(&ar->fw_recovery.hb_timer);
 	cancel_work_sync(&ar->fw_recovery.recovery_work);
 }
 
@@ -56,7 +121,27 @@ void ath6kl_recovery_suspend(struct ath6kl *ar)
 {
 	ath6kl_recovery_cleanup(ar);
 
+	if (!ar->fw_recovery.err_reason)
+		return;
+
 	/* Process pending fw error detection */
-	if (ar->fw_recovery.err_reason)
-		ath6kl_init_hw_restart(ar);
+	ar->fw_recovery.err_reason = 0;
+	WARN_ON(ar->state != ATH6KL_STATE_ON);
+	ar->state = ATH6KL_STATE_RECOVERY;
+	ath6kl_init_hw_restart(ar);
+	ar->state = ATH6KL_STATE_ON;
+}
+
+void ath6kl_recovery_resume(struct ath6kl *ar)
+{
+	ar->fw_recovery.enable = true;
+
+	if (!ar->fw_recovery.hb_poll)
+		return;
+
+	ar->fw_recovery.hb_pending = false;
+	ar->fw_recovery.seq_num = 0;
+	ar->fw_recovery.hb_misscnt = 0;
+	mod_timer(&ar->fw_recovery.hb_timer,
+		  jiffies + msecs_to_jiffies(ar->fw_recovery.hb_poll));
 }