[PATCH net 2/2] ethtool: cmis: use u16 for calculated read_write_len_ext

[Michael Chan <michael.chan@broadcom.com>]

From: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>

For EPL (Extended Payload), the maximum calculated size returned by
ethtool_cmis_get_max_epl_size() is 2048, so the read_write_len_ext
field in struct ethtool_cmis_cdb_cmd_args needs to be changed to u16
to hold the value.

To avoid confusion with other u8 read_write_len_ext fields defined
by the CMIS spec, change the field name to calc_read_write_len_ext.

Without this change, module flashing can fail:

Transceiver module firmware flashing started for device enp177s0np0
Transceiver module firmware flashing in progress for device enp177s0np0
Progress: 0%
Transceiver module firmware flashing encountered an error for device enp177s0np0
Status message: Write FW block EPL command failed, LPL length is longer
	than CDB read write length extension allows.

Fixes: a39c84d79625 ("ethtool: cmis_cdb: Add a layer for supporting CDB commands)
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 net/ethtool/cmis.h     | 7 ++++---
 net/ethtool/cmis_cdb.c | 8 ++++----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/net/ethtool/cmis.h b/net/ethtool/cmis.h
index 1e790413db0e..51f5d5439e2a 100644
--- a/net/ethtool/cmis.h
+++ b/net/ethtool/cmis.h
@@ -63,8 +63,9 @@ struct ethtool_cmis_cdb_request {
  * struct ethtool_cmis_cdb_cmd_args - CDB commands execution arguments
  * @req: CDB command fields as described in the CMIS standard.
  * @max_duration: Maximum duration time for command completion in msec.
- * @read_write_len_ext: Allowable additional number of byte octets to the LPL
- *			in a READ or a WRITE commands.
+ * @calc_read_write_len_ext: Calculated allowable additional number of byte
+ *			     octets to the LPL or EPL in a READ or WRITE CDB
+ *			     command.
  * @msleep_pre_rpl: Waiting time before checking reply in msec.
  * @rpl_exp_len: Expected reply length in bytes.
  * @flags: Validation flags for CDB commands.
@@ -73,7 +74,7 @@ struct ethtool_cmis_cdb_request {
 struct ethtool_cmis_cdb_cmd_args {
 	struct ethtool_cmis_cdb_request req;
 	u16				max_duration;
-	u8				read_write_len_ext;
+	u16				calc_read_write_len_ext;
 	u8				msleep_pre_rpl;
 	u8                              rpl_exp_len;
 	u8				flags;
diff --git a/net/ethtool/cmis_cdb.c b/net/ethtool/cmis_cdb.c
index dba3aa909a95..1f487e1a6347 100644
--- a/net/ethtool/cmis_cdb.c
+++ b/net/ethtool/cmis_cdb.c
@@ -35,13 +35,13 @@ void ethtool_cmis_cdb_compose_args(struct ethtool_cmis_cdb_cmd_args *args,
 	args->req.lpl_len = lpl_len;
 	if (lpl) {
 		memcpy(args->req.payload, lpl, args->req.lpl_len);
-		args->read_write_len_ext =
+		args->calc_read_write_len_ext =
 			ethtool_cmis_get_max_lpl_size(read_write_len_ext);
 	}
 	if (epl) {
 		args->req.epl_len = cpu_to_be16(epl_len);
 		args->req.epl = epl;
-		args->read_write_len_ext =
+		args->calc_read_write_len_ext =
 			ethtool_cmis_get_max_epl_size(read_write_len_ext);
 	}
 
@@ -590,7 +590,7 @@ ethtool_cmis_cdb_execute_epl_cmd(struct net_device *dev,
 			space_left = CMIS_CDB_EPL_FW_BLOCK_OFFSET_END - offset + 1;
 			bytes_to_write = min_t(u16, bytes_left,
 					       min_t(u16, space_left,
-						     args->read_write_len_ext));
+						     args->calc_read_write_len_ext));
 
 			err = __ethtool_cmis_cdb_execute_cmd(dev, page_data,
 							     page, offset,
@@ -631,7 +631,7 @@ int ethtool_cmis_cdb_execute_cmd(struct net_device *dev,
 				       offsetof(struct ethtool_cmis_cdb_request,
 						epl));
 
-	if (args->req.lpl_len > args->read_write_len_ext) {
+	if (args->req.lpl_len > args->calc_read_write_len_ext) {
 		args->err_msg = "LPL length is longer than CDB read write length extension allows";
 		return -EINVAL;
 	}
-- 
2.30.1