ath6kl: Retain bg scan period value modified by the user

Added a new member bg_scan_period in struct ath6kl_vif
to retain background scan period value configured via debugfs
entry 'bgscan_interval'. This backup is needed in schedule scan
path while configuring scan parameters.
Signed-off-by: Raja Mani <rmani@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/cfg80211.c

@@ -3370,6 +3370,7 @@ struct net_device *ath6kl_interface_add(struct ath6kl *ar, char *name,
 	vif->next_mode = nw_type;
 	vif->listen_intvl_t = ATH6KL_DEFAULT_LISTEN_INTVAL;
 	vif->bmiss_time_t = ATH6KL_DEFAULT_BMISS_TIME;
+	vif->bg_scan_period = 0;
 	vif->htcap.ht_enable = true;
 
 	memcpy(ndev->dev_addr, ar->mac_addr, ETH_ALEN);

drivers/net/wireless/ath/ath6kl/core.h

@@ -557,6 +557,7 @@ struct ath6kl_vif {
 	u16 assoc_bss_beacon_int;
 	u16 listen_intvl_t;
 	u16 bmiss_time_t;
+	u16 bg_scan_period;
 	u8 assoc_bss_dtim_period;
 	struct net_device_stats net_stats;
 	struct target_stats target_stats;

drivers/net/wireless/ath/ath6kl/debug.c

@@ -1578,10 +1578,15 @@ static ssize_t ath6kl_bgscan_int_write(struct file *file,
 				size_t count, loff_t *ppos)
 {
 	struct ath6kl *ar = file->private_data;
+	struct ath6kl_vif *vif;
 	u16 bgscan_int;
 	char buf[32];
 	ssize_t len;
 
+	vif = ath6kl_vif_first(ar);
+	if (!vif)
+		return -EIO;
+
 	len = min(count, sizeof(buf) - 1);
 	if (copy_from_user(buf, user_buf, len))
 		return -EFAULT;
@@ -1593,6 +1598,8 @@ static ssize_t ath6kl_bgscan_int_write(struct file *file,
 	if (bgscan_int == 0)
 		bgscan_int = 0xffff;
 
+	vif->bg_scan_period = bgscan_int;
+
 	ath6kl_wmi_scanparams_cmd(ar->wmi, 0, 0, 0, bgscan_int, 0, 0, 0, 3,
 				  0, 0, 0);