net: phy: sfp: Handle unimplemented hwmon limits and alarms

Not all SFPs implement the registers containing sensor limits and
alarms. Luckily, there is a bit indicating if they are implemented or
not. Add checking for this bit, when deciding if the hwmon attributes
should be visible.

Fixes: 1323061a018a ("net: phy: sfp: Add HWMON support for module sensors")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/sfp.c

@@ -398,7 +398,6 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 	switch (type) {
 	case hwmon_temp:
 		switch (attr) {
-		case hwmon_temp_input:
 		case hwmon_temp_min_alarm:
 		case hwmon_temp_max_alarm:
 		case hwmon_temp_lcrit_alarm:
@@ -407,13 +406,16 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 		case hwmon_temp_max:
 		case hwmon_temp_lcrit:
 		case hwmon_temp_crit:
+			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
+				return 0;
+			/* fall through */
+		case hwmon_temp_input:
 			return 0444;
 		default:
 			return 0;
 		}
 	case hwmon_in:
 		switch (attr) {
-		case hwmon_in_input:
 		case hwmon_in_min_alarm:
 		case hwmon_in_max_alarm:
 		case hwmon_in_lcrit_alarm:
@@ -422,13 +424,16 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 		case hwmon_in_max:
 		case hwmon_in_lcrit:
 		case hwmon_in_crit:
+			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
+				return 0;
+			/* fall through */
+		case hwmon_in_input:
 			return 0444;
 		default:
 			return 0;
 		}
 	case hwmon_curr:
 		switch (attr) {
-		case hwmon_curr_input:
 		case hwmon_curr_min_alarm:
 		case hwmon_curr_max_alarm:
 		case hwmon_curr_lcrit_alarm:
@@ -437,6 +442,10 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 		case hwmon_curr_max:
 		case hwmon_curr_lcrit:
 		case hwmon_curr_crit:
+			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
+				return 0;
+			/* fall through */
+		case hwmon_curr_input:
 			return 0444;
 		default:
 			return 0;
@@ -452,7 +461,6 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 		    channel == 1)
 			return 0;
 		switch (attr) {
-		case hwmon_power_input:
 		case hwmon_power_min_alarm:
 		case hwmon_power_max_alarm:
 		case hwmon_power_lcrit_alarm:
@@ -461,6 +469,10 @@ static umode_t sfp_hwmon_is_visible(const void *data,
 		case hwmon_power_max:
 		case hwmon_power_lcrit:
 		case hwmon_power_crit:
+			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
+				return 0;
+			/* fall through */
+		case hwmon_power_input:
 			return 0444;
 		default:
 			return 0;