sfc: Return an error code when a sensor is busy.

[bwh: Also name this new state, though we don't expect to see it in an event]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/mcdi_mon.c b/drivers/net/ethernet/sfc/mcdi_mon.c
index 958c73faa523bab7be85c705fefdf3766129acdf..544889baceccfaaf7ec90f29e720b3a8c92b2f4a 100644 (file)
--- a/drivers/net/ethernet/sfc/mcdi_mon.c
+++ b/drivers/net/ethernet/sfc/mcdi_mon.c
@@ -54,6 +54,7 @@ static const char *const sensor_status_names[] = {
        [MC_CMD_SENSOR_STATE_WARNING] = "Warning",
        [MC_CMD_SENSOR_STATE_FATAL] = "Fatal",
        [MC_CMD_SENSOR_STATE_BROKEN] = "Device failure",
+       [MC_CMD_SENSOR_STATE_NO_READING] = "No reading",
 };
 
 void efx_mcdi_sensor_event(struct efx_nic *efx, efx_qword_t *ev)
@@ -144,13 +145,17 @@ static ssize_t efx_mcdi_mon_show_value(struct device *dev,
        struct efx_mcdi_mon_attribute *mon_attr =
                container_of(attr, struct efx_mcdi_mon_attribute, dev_attr);
        efx_dword_t entry;
-       unsigned int value;
+       unsigned int value, state;
        int rc;
 
        rc = efx_mcdi_mon_get_entry(dev, mon_attr->index, &entry);
        if (rc)
                return rc;
 
+       state = EFX_DWORD_FIELD(entry, MC_CMD_SENSOR_VALUE_ENTRY_TYPEDEF_STATE);
+       if (state == MC_CMD_SENSOR_STATE_NO_READING)
+               return -EBUSY;
+
        value = EFX_DWORD_FIELD(entry, MC_CMD_SENSOR_VALUE_ENTRY_TYPEDEF_VALUE);
 
        /* Convert temperature from degrees to milli-degrees Celsius */