habanalabs: add missing error check in sysfs max_power_show

Add a missing error check in the sysfs show function for max_power.
Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

drivers/misc/habanalabs/common/firmware_if.c

@@ -2780,7 +2780,7 @@ void hl_fw_set_frequency(struct hl_device *hdev, u32 pll_index, u64 freq)
 			used_pll_idx, rc);
 }
 
-u64 hl_fw_get_max_power(struct hl_device *hdev)
+long hl_fw_get_max_power(struct hl_device *hdev)
 {
 	struct cpucp_packet pkt;
 	u64 result;
@@ -2794,7 +2794,7 @@ u64 hl_fw_get_max_power(struct hl_device *hdev)
 
 	if (rc) {
 		dev_err(hdev->dev, "Failed to get max power, error %d\n", rc);
-		return (u64) rc;
+		return rc;
 	}
 
 	return result;

drivers/misc/habanalabs/common/habanalabs.h

@@ -3098,7 +3098,7 @@ int hl_get_current(struct hl_device *hdev, int sensor_index, u32 attr, long *val
 int hl_get_fan_speed(struct hl_device *hdev, int sensor_index, u32 attr, long *value);
 int hl_get_pwm_info(struct hl_device *hdev, int sensor_index, u32 attr, long *value);
 void hl_set_pwm_info(struct hl_device *hdev, int sensor_index, u32 attr, long value);
-u64 hl_fw_get_max_power(struct hl_device *hdev);
+long hl_fw_get_max_power(struct hl_device *hdev);
 void hl_fw_set_max_power(struct hl_device *hdev);
 int hl_set_voltage(struct hl_device *hdev, int sensor_index, u32 attr, long value);
 int hl_set_current(struct hl_device *hdev, int sensor_index, u32 attr, long value);

drivers/misc/habanalabs/common/sysfs.c

@@ -304,6 +304,8 @@ static ssize_t max_power_show(struct device *dev, struct device_attribute *attr,
 		return -ENODEV;
 
 	val = hl_fw_get_max_power(hdev);
+	if (val < 0)
+		return val;
 
 	return sprintf(buf, "%lu\n", val);
 }