[char-misc-next] mei: support HBM versioning

From: Tomas Winkler
Date: Sun Jun 16 2013 - 02:19:19 EST


Driver can work properly if device support driver HBM version
or driver can downgrade its supported HBM version level

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/misc/mei/hbm.c | 37 ++++++++++++++++++++++++++++++++-----
drivers/misc/mei/hbm.h | 2 +-
drivers/misc/mei/init.c | 3 +--
3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index 6916045..565027b 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -536,6 +536,20 @@ static void mei_hbm_fw_disconnect_req(struct mei_device *dev,


/**
+ * mei_hbm_version_is_supported - checks whether the driver can
+ * support the hbm version of the device
+ *
+ * @dev: the device structure
+ * returns true if driver can support hbm version of the device
+ */
+bool mei_hbm_version_is_supported(struct mei_device *dev)
+{
+ return (dev->version.major_version < HBM_MAJOR_VERSION) ||
+ (dev->version.major_version == HBM_MAJOR_VERSION &&
+ dev->version.minor_version <= HBM_MINOR_VERSION);
+}
+
+/**
* mei_hbm_dispatch - bottom half read routine after ISR to
* handle the read bus message cmd processing.
*
@@ -562,9 +576,24 @@ void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
switch (mei_msg->hbm_cmd) {
case HOST_START_RES_CMD:
version_res = (struct hbm_host_version_response *)mei_msg;
- if (!version_res->host_version_supported) {
- dev->version = version_res->me_max_version;
- dev_dbg(&dev->pdev->dev, "version mismatch.\n");
+
+ dev_dbg(&dev->pdev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
+ HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
+ version_res->me_max_version.major_version,
+ version_res->me_max_version.minor_version);
+
+ if (version_res->host_version_supported) {
+ dev->version.major_version = HBM_MAJOR_VERSION;
+ dev->version.minor_version = HBM_MINOR_VERSION;
+ } else {
+ dev->version.major_version =
+ version_res->me_max_version.major_version;
+ dev->version.minor_version =
+ version_res->me_max_version.minor_version;
+ }
+
+ if (!mei_hbm_version_is_supported(dev)) {
+ dev_warn(&dev->pdev->dev, "hbm version mismatch: stopping the driver.\n");

dev->hbm_state = MEI_HBM_STOP;
mei_hbm_stop_req_prepare(dev, &dev->wr_msg.hdr,
@@ -575,8 +604,6 @@ void mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
return;
}

- dev->version.major_version = HBM_MAJOR_VERSION;
- dev->version.minor_version = HBM_MINOR_VERSION;
if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
dev->hbm_state == MEI_HBM_START) {
dev->init_clients_timer = 0;
diff --git a/drivers/misc/mei/hbm.h b/drivers/misc/mei/hbm.h
index e80dc24..4ae2e56 100644
--- a/drivers/misc/mei/hbm.h
+++ b/drivers/misc/mei/hbm.h
@@ -54,7 +54,7 @@ int mei_hbm_start_wait(struct mei_device *dev);
int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl);
int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl);
int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl);
-
+bool mei_hbm_version_is_supported(struct mei_device *dev);

#endif /* _MEI_HBM_H_ */

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index f580d30..79e9e1c 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -106,8 +106,7 @@ int mei_start(struct mei_device *dev)
goto err;
}

- if (dev->version.major_version != HBM_MAJOR_VERSION ||
- dev->version.minor_version != HBM_MINOR_VERSION) {
+ if (!mei_hbm_version_is_supported(dev)) {
dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
goto err;
}
--
1.8.1.2

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