wlan: Block interface down until pending scan request is aborted
From Kernel-3.18 onwards pending scan request is handled
as part of NETDEV_DOWN event, by invoking the cfg80211_scan_done
callback which frees the scan request structure. To support this,
driver will not invoke scan_done_callback if interface is down.
In case, if interface down and up are called back to back there
is a chance that kernel frees scan request as part of NETDEV_DOWN
and after which before driver triggers scan_done_callback if
interface is made up, driver scan_done_callback is through its
execution and accesses the freed scan request results in kernel
panic.
To mitigate this, don't return from hdd_stop until scan request
is aborted. Though this fix is to avoid kernel panic due to 3.18
kernel specific changes, it is acceptable across all the kernel
versions.
Change-Id: Iba8bd7a32fac33e8a0c3eea293aad682a1105397
CRs-Fixed: 977264
1 file changed