qcacmn: Roam control configuration for 6 GHz in full scan only on prior discovery

During the roam scan, if there are no desired APs found in the partial
frequency list, an immediate full scan on all the supported frequencies
is initiated as a fallback. This would include the 6 GHz PSC
frequencies. Define an attribute to allow that behavior to be modified
to include PSCs only if 6 GHz use has been detected.

Change-Id: I81eb9b20c2953e6b0dbf4138b31547db82d7397f
CRs-Fixed: 3351706

os_if/linux/qca_vendor.h

@@ -3545,6 +3545,24 @@ enum qca_vendor_attr_roam_candidate_selection_criteria {
  *	If this flag is not specified, a full scan shall include all the
  *	supported frequencies irrespective of the ones part of an earlier
  *	partial scan.
+ *
+ * @QCA_ATTR_ROAM_CONTROL_FULL_SCAN_6GHZ_ONLY_ON_PRIOR_DISCOVERY: Unsigned 8-bit
+ *	value.
+ *	During the roam scan, if there are no desired APs found in the partial
+ *	frequency list, an immediate full scan on all the supported frequencies
+ *	is initiated as a fallback. This full scan would add the 2.4/5/6 GHz
+ *	frequencies, including all PSC frequencies by default. This attribute
+ *	controls the inclusion of the 6 GHz PSC frequencies for the full scan
+ *	as following.
+ *	1 - Full scan to include the supported 6 GHz PSC frequencies only on the
+ *	    prior discovery of any 6 GHz frequency support in the environment.
+ *	    This discovery can happen through a prior RNR, 11k neighbor
+ *	    request, 11v BTM request, host scan, etc.
+ *	0 - Default behavior. Full scan to include all the supported 6 GHz
+ *	    PSC frequencies regardless of whether 6 GHz BSSs have been
+ *	    discovered.
+ *	The default behavior if this flag is not specified is to include all
+ *	the supported 6 GHz PSC frequencies in the roam full scan.
  */
 enum qca_vendor_attr_roam_control {
 	QCA_ATTR_ROAM_CONTROL_ENABLE = 1,
@@ -3567,6 +3585,7 @@ enum qca_vendor_attr_roam_control {
 	QCA_ATTR_ROAM_CONTROL_RX_LINKSPEED_THRESHOLD = 24,
 	QCA_ATTR_ROAM_CONTROL_HO_DELAY_FOR_RX = 25,
 	QCA_ATTR_ROAM_CONTROL_FULL_SCAN_NO_REUSE_PARTIAL_SCAN_FREQ = 26,
+	QCA_ATTR_ROAM_CONTROL_FULL_SCAN_6GHZ_ONLY_ON_PRIOR_DISCOVERY = 27,
 
 	/* keep last */
 	QCA_ATTR_ROAM_CONTROL_AFTER_LAST,