mei: obtain firmware version only on gsc.

Modern GSC firmwares have both static and dynamic MKHI clients.
Avoid expensive dynamic client call for firmware version retrieval,
in case the firmware version is already retrieved from the fix address
client in bus_fixup().
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20230716081043.3092690-3-tomas.winkler@intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus-fixup.c

@@ -184,6 +184,7 @@ static int mei_fwver(struct mei_cl_device *cldev)
 		cldev->bus->fw_ver[i].hotfix = fwver->ver[i].hotfix;
 		cldev->bus->fw_ver[i].buildno = fwver->ver[i].buildno;
 	}
+	cldev->bus->fw_ver_received = 1;
 
 	return ret;
 }
@@ -237,8 +238,11 @@ static void mei_gsc_mkhi_ver(struct mei_cl_device *cldev)
 {
 	int ret;
 
-	/* No need to enable the client if nothing is needed from it */
-	if (!cldev->bus->fw_f_fw_ver_supported)
+	/*
+	 * No need to enable the client if nothing is needed from it.
+	 * No need to fill in version if it is already filled in by the fix address client.
+	 */
+	if (!cldev->bus->fw_f_fw_ver_supported || cldev->bus->fw_ver_received)
 		return;
 
 	ret = mei_cldev_enable(cldev);
@@ -555,8 +559,8 @@ static struct mei_fixup {
 	MEI_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
 	MEI_FIXUP(MEI_UUID_WD, mei_wd),
 	MEI_FIXUP(MEI_UUID_MKHIF_FIX, mei_mkhi_fix),
-	MEI_FIXUP(MEI_UUID_IGSC_MKHI, mei_gsc_mkhi_ver),
 	MEI_FIXUP(MEI_UUID_IGSC_MKHI_FIX, mei_gsc_mkhi_fix_ver),
+	MEI_FIXUP(MEI_UUID_IGSC_MKHI, mei_gsc_mkhi_ver),
 	MEI_FIXUP(MEI_UUID_HDCP, whitelist),
 	MEI_FIXUP(MEI_UUID_ANY, vt_support),
 	MEI_FIXUP(MEI_UUID_PAVP, pxp_is_ready),

drivers/misc/mei/init.c

@@ -142,6 +142,9 @@ int mei_reset(struct mei_device *dev)
 
 	mei_hbm_reset(dev);
 
+	/* clean stale FW version */
+	dev->fw_ver_received = 0;
+
 	memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 
 	if (ret) {

drivers/misc/mei/mei_dev.h

@@ -512,6 +512,7 @@ struct mei_dev_timeouts {
  * @fw_ver : FW versions
  *
  * @fw_f_fw_ver_supported : fw feature: fw version supported
+ * @fw_ver_received : fw version received
  *
  * @me_clients_rwsem: rw lock over me_clients list
  * @me_clients  : list of FW clients
@@ -604,6 +605,7 @@ struct mei_device {
 	struct mei_fw_version fw_ver[MEI_MAX_FW_VER_BLOCKS];
 
 	unsigned int fw_f_fw_ver_supported:1;
+	unsigned int fw_ver_received:1;
 
 	struct rw_semaphore me_clients_rwsem;
 	struct list_head me_clients;