UPSTREAM: mwifiex: fix incomplete scan in case of IE parsing error

A scan request is split into multiple scan commands queued in
scan_pending_q. Each scan command will be sent to firmware and
its response is handlded one after another.

If any error is detected while parsing IE in command response
buffer the remaining data will be ignored and error is returned.

We should check if there is any more scan commands pending in
the queue before returning error. This ensures that we will call
cfg80211_scan_done if this is the last scan command, or send
next scan command in scan_pending_q to firmware.

Cc: "3.6+" <stable@vger.kernel.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
BUG=none
TEST=Hacked the driver to simulate an IE parsing error.
Without this patch, "iw mlan0 scan" gets stuck.
With this patch applied, "iw mlan0 scan" returns AP list.

Change-Id: I93cb877650ad9e84e5109f4ea62cf5b5c638e26a
Reviewed-on: https://gerrit.chromium.org/gerrit/42377
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Bing Zhao <bzhao@marvell.com>
Tested-by: Bing Zhao <bzhao@marvell.com>

diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index c152a39..0b51328 100644 (file)
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -1536,7 +1536,7 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                dev_err(adapter->dev, "SCAN_RESP: too many AP returned (%d)\n",
                        scan_rsp->number_of_sets);
                ret = -1;
-               goto done;
+               goto check_next_scan;
        }
 
        bytes_left = le16_to_cpu(scan_rsp->bss_descript_size);
@@ -1607,7 +1607,8 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                if (!beacon_size || beacon_size > bytes_left) {
                        bss_info += bytes_left;
                        bytes_left = 0;
-                       return -1;
+                       ret = -1;
+                       goto check_next_scan;
                }
 
                /* Initialize the current working beacon pointer for this BSS
@@ -1663,7 +1664,7 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                                dev_err(priv->adapter->dev,
                                        "%s: bytes left < IE length\n",
                                        __func__);
-                               goto done;
+                               goto check_next_scan;
                        }
                        if (element_id == WLAN_EID_DS_PARAMS) {
                                channel = *(u8 *) (current_ptr +
@@ -1727,6 +1728,7 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                }
        }
 
+check_next_scan:
        spin_lock_irqsave(&adapter->scan_pending_q_lock, flags);
        if (list_empty(&adapter->scan_pending_q)) {
                spin_unlock_irqrestore(&adapter->scan_pending_q_lock, flags);
@@ -1787,7 +1789,6 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                }
        }
 
-done:
        return ret;
 }