mlxsw: core: Reduce buffer size in transactions for SFP modules temperature readout

Obtain SFP modules temperatures through MTMP register instead of MTBR
register, because the first one utilizes shorter transaction buffer size
for request. It improves performance in case low frequency interface
(I2C) is used for communication with a chip.

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 27 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
index d3e851e7ca72..cfab0e330a47 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
@@ -449,39 +449,31 @@ static int mlxsw_thermal_module_temp_get(struct thermal_zone_device *tzdev,
 	struct mlxsw_thermal_module *tz = tzdev->devdata;
 	struct mlxsw_thermal *thermal = tz->parent;
 	struct device *dev = thermal->bus_info->dev;
-	char mtbr_pl[MLXSW_REG_MTBR_LEN];
-	u16 temp;
+	char mtmp_pl[MLXSW_REG_MTMP_LEN];
+	unsigned int temp;
 	int err;
 
 	/* Read module temperature. */
-	mlxsw_reg_mtbr_pack(mtbr_pl, MLXSW_REG_MTBR_BASE_MODULE_INDEX +
-			    tz->module, 1);
-	err = mlxsw_reg_query(thermal->core, MLXSW_REG(mtbr), mtbr_pl);
-	if (err)
-		return err;
-
-	mlxsw_reg_mtbr_temp_unpack(mtbr_pl, 0, &temp, NULL);
-	/* Update temperature. */
-	switch (temp) {
-	case MLXSW_REG_MTBR_NO_CONN: /* fall-through */
-	case MLXSW_REG_MTBR_NO_TEMP_SENS: /* fall-through */
-	case MLXSW_REG_MTBR_INDEX_NA: /* fall-through */
-	case MLXSW_REG_MTBR_BAD_SENS_INFO:
+	mlxsw_reg_mtmp_pack(mtmp_pl, MLXSW_REG_MTMP_MODULE_INDEX_MIN +
+			    tz->module, false, false);
+	err = mlxsw_reg_query(thermal->core, MLXSW_REG(mtmp), mtmp_pl);
+	if (err) {
+		/* Do not return error - in case of broken module's sensor
+		 * it will cause error message flooding.
+		 */
 		temp = 0;
-		break;
-	default:
-		temp = MLXSW_REG_MTMP_TEMP_TO_MC(temp);
-		/* Reset all trip point. */
-		mlxsw_thermal_module_trips_reset(tz);
-		/* Update trip points. */
-		err = mlxsw_thermal_module_trips_update(dev, thermal->core,
-							tz);
-		if (err)
-			return err;
-		break;
+		*p_temp = (int) temp;
+		return 0;
 	}
-
+	mlxsw_reg_mtmp_unpack(mtmp_pl, &temp, NULL, NULL);
 	*p_temp = (int) temp;
+
+	if (!temp)
+		return 0;
+
+	/* Update trip points. */
+	mlxsw_thermal_module_trips_update(dev, thermal->core, tz);
+
 	return 0;
 }