[PATCH 6/6] staging: fsl-mc: Changed version matching rules for MC object drivers

[J. German Rivera]

Before this change, we were requiring a complete version match (major and
minor version numbers) between MC objects and corresponding drivers, to
allow MC objects to be bound to their drivers. We realized that a mismatch
in minor version numbers should be tolerated, as long as the major version
numbers match. This allows the driver to decide what to do in the minor
version mismatch case. For example, a driver may decide to run with
downgraded functionality if the MC firmware object has older minor version
number than the driver. Also, a driver with older minor version than the
MC firmware object may decide to run even though it cannot use newer
functionality of the MC object.

As part of this change, the dpmng Flib version was also updated
to match the latest MC firmware version.

Signed-off-by: J. German Rivera <German.Rivera at freescale.com>
---
 drivers/staging/fsl-mc/bus/mc-bus.c    | 29 +++++++++++++++++++++++++----
 drivers/staging/fsl-mc/include/dpmng.h |  2 +-
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/fsl-mc/bus/mc-bus.c b/drivers/staging/fsl-mc/bus/mc-bus.c
index b347db9..23512d0 100644
--- a/drivers/staging/fsl-mc/bus/mc-bus.c
+++ b/drivers/staging/fsl-mc/bus/mc-bus.c
@@ -36,6 +36,8 @@ static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv)
 	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
 	struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv);
 	bool found = false;
+	bool major_version_mismatch = false;
+	bool minor_version_mismatch = false;
 
 	if (WARN_ON(!fsl_mc_bus_type.dev_root))
 		goto out;
@@ -57,14 +59,33 @@ static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv)
 	 */
 	for (id = mc_drv->match_id_table; id->vendor != 0x0; id++) {
 		if (id->vendor == mc_dev->obj_desc.vendor &&
-		    strcmp(id->obj_type, mc_dev->obj_desc.type) == 0 &&
-		    id->ver_major == mc_dev->obj_desc.ver_major &&
-		    id->ver_minor == mc_dev->obj_desc.ver_minor) {
-			found = true;
+		    strcmp(id->obj_type, mc_dev->obj_desc.type) == 0) {
+			if (id->ver_major == mc_dev->obj_desc.ver_major) {
+				found = true;
+				if (id->ver_minor != mc_dev->obj_desc.ver_minor)
+					minor_version_mismatch = true;
+			} else {
+				major_version_mismatch = true;
+			}
+
 			break;
 		}
 	}
 
+	if (major_version_mismatch) {
+		dev_warn(dev,
+			 "Major version mismatch: driver version %u.%u, MC object version %u.%u\n",
+			 id->ver_major, id->ver_minor,
+			 mc_dev->obj_desc.ver_major,
+			 mc_dev->obj_desc.ver_minor);
+	} else if (minor_version_mismatch) {
+		dev_warn(dev,
+			 "Minor version mismatch: driver version %u.%u, MC object version %u.%u\n",
+			 id->ver_major, id->ver_minor,
+			 mc_dev->obj_desc.ver_major,
+			 mc_dev->obj_desc.ver_minor);
+	}
+
 out:
 	dev_dbg(dev, "%smatched\n", found ? "" : "not ");
 	return found;
diff --git a/drivers/staging/fsl-mc/include/dpmng.h b/drivers/staging/fsl-mc/include/dpmng.h
index 0fc0a57..1b052b8 100644
--- a/drivers/staging/fsl-mc/include/dpmng.h
+++ b/drivers/staging/fsl-mc/include/dpmng.h
@@ -41,7 +41,7 @@ struct fsl_mc_io;
 /**
  * Management Complex firmware version information
  */
-#define MC_VER_MAJOR 5
+#define MC_VER_MAJOR 6
 #define MC_VER_MINOR 0
 
 /**
-- 
2.3.3