wcn36xx: Fix beacon loss detection during sw scanath.master-03-11-20+wcn36xx-fw-offload-suspend-resume-t1

Testing on Android - which has a tendency to hammer away at WiFi scanning
I've found that if I disconnect an AP - literally pull the power out during
a scan that a loss of beacon indication is not generated by the firmware.

Instead the undocumented result code '29' is returned. The set of declared
response codes in downstream prima is.

typedef enum
{
   WDI_STATUS_SUCCESS,
   WDI_STATUS_SUCCESS_SYNC,
   WDI_STATUS_PENDING,
   WDI_STATUS_E_FAILURE,
   WDI_STATUS_RES_FAILURE,
   WDI_STATUS_MEM_FAILURE,
   WDI_STATUS_E_NOT_ALLOWED,
   WDI_STATUS_E_NOT_IMPLEMENT,
   WDI_STATUS_DEV_INTERNAL_FAILURE,
   WDI_STATUS_MAX
}WDI_Status;

No sign of 29 in this list, let alone what it indicates.

What we see when a scan is not in progress is the firmware generate a
beacon loss indication which then flows down into
wcn36xx_smd_missed_beacon_ind().

This patch addresses this difference in behavior by:

1. Capturing the result code of wcn36xx_smd_init_scan()
2. If and only if a software scan is in progress and we are associated with
   an AP triggering ieee80211_connection_loss()

Once done I can reliably capture beacon loss both on the scan and non-scan
paths.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/net/wireless/ath/wcn36xx/main.c b/drivers/net/wireless/ath/wcn36xx/main.c
index 5867bd9c2f64..e73d04ef2072 100644
--- a/drivers/net/wireless/ath/wcn36xx/main.c
+++ b/drivers/net/wireless/ath/wcn36xx/main.c
@@ -406,6 +406,8 @@ static void wcn36xx_change_opchannel(struct wcn36xx *wcn, int ch)
 static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed)
 {
 	struct wcn36xx *wcn = hw->priv;
+	struct wcn36xx_vif *vif_priv;
+	int ret;
 
 	wcn36xx_dbg(WCN36XX_DBG_MAC, "mac config changed 0x%08x\n", changed);
 
@@ -427,9 +429,15 @@ static int wcn36xx_config(struct ieee80211_hw *hw, u32 changed)
 			/* A scan is ongoing, do not change the operating
 			 * channel, but start a scan session on the channel.
 			 */
-			wcn36xx_smd_init_scan(wcn, HAL_SYS_MODE_SCAN,
-					      wcn->sw_scan_vif);
-			wcn36xx_smd_start_scan(wcn, ch);
+			ret = wcn36xx_smd_init_scan(wcn, HAL_SYS_MODE_SCAN,
+						    wcn->sw_scan_vif);
+			if (ret && wcn->sw_scan == true) {
+				vif_priv = wcn36xx_vif_to_priv(wcn->sw_scan_vif);
+				if (vif_priv->sta_assoc)
+					ieee80211_connection_loss(wcn->sw_scan_vif);
+			} else {
+				wcn36xx_smd_start_scan(wcn, ch);
+			}
 		} else {
 			wcn36xx_change_opchannel(wcn, ch);
 		}