[PATCH 3/3] wcn36xx: don't delete invalid bss indices

[Daniel Mack <daniel@zonque.org>]

The firmware code cannot cope with requests to remove BSS indices that have
not previously been added. This primarily happens when the device is
suspended and then resumed. ieee80211_reconfig() then calls into
wcn36xx_bss_info_changed() with an empty bssid and BSS_CHANGED_BSSID set,
which subsequently leads to a firmware crash:

[   43.647928] qcom-wcnss-pil a204000.wcnss: fatal error received: halMsg.c:4964:halMsg_DelBss: Invalid BSSIndex 0
[   43.647959] remoteproc remoteproc0: crash detected in a204000.wcnss: type fatal error

To fix this, set bss_index to WCN36XX_HAL_BSS_INVALID_IDX for all bss
that have not been configured in the firmware, and don't call into the
firmware with invalid indices.

Signed-off-by: Daniel Mack <daniel@zonque.org>
---
 drivers/net/wireless/ath/wcn36xx/main.c | 1 +
 drivers/net/wireless/ath/wcn36xx/smd.c  | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
index 69d6be59d97f..32bbd6e2fd09 100644
--- a/drivers/net/wireless/ath/wcn36xx/main.c
+++ b/drivers/net/wireless/ath/wcn36xx/main.c
@@ -953,6 +953,7 @@ static int wcn36xx_add_interface(struct ieee80211_hw *hw,
 
 	mutex_lock(&wcn->conf_mutex);
 
+	vif_priv->bss_index = WCN36XX_HAL_BSS_INVALID_IDX;
 	list_add(&vif_priv->list, &wcn->vif_list);
 	wcn36xx_smd_add_sta_self(wcn, vif);
 
diff --git a/drivers/net/wireless/ath/wcn36xx/smd.c b/drivers/net/wireless/ath/wcn36xx/smd.c
index 8932af5e4d8d..5be07e40a86d 100644
--- a/drivers/net/wireless/ath/wcn36xx/smd.c
+++ b/drivers/net/wireless/ath/wcn36xx/smd.c
@@ -1446,6 +1446,10 @@ int wcn36xx_smd_delete_bss(struct wcn36xx *wcn, struct ieee80211_vif *vif)
 	int ret = 0;
 
 	mutex_lock(&wcn->hal_mutex);
+
+	if (vif_priv->bss_index == WCN36XX_HAL_BSS_INVALID_IDX)
+		goto out;
+
 	INIT_HAL_MSG(msg_body, WCN36XX_HAL_DELETE_BSS_REQ);
 
 	msg_body.bss_index = vif_priv->bss_index;
@@ -1464,6 +1468,8 @@ int wcn36xx_smd_delete_bss(struct wcn36xx *wcn, struct ieee80211_vif *vif)
 		wcn36xx_err("hal_delete_bss response failed err=%d\n", ret);
 		goto out;
 	}
+
+	vif_priv->bss_index = WCN36XX_HAL_BSS_INVALID_IDX;
 out:
 	mutex_unlock(&wcn->hal_mutex);
 	return ret;
-- 
2.14.3