On i.MX8MQ, enabling monitoring sites that aren't connected to anything can cause unwanted side effects on some units. This seems to happen once some of these sites report out-of-range readings and results in sensor misbehavior, such as thermal zone readings getting stuck or even suddenly reporting an impossibly high value, triggering emergency shutdowns.
The datasheet lists all non-existent sites as "reserved" and doesn't make any guarantees about being able to enable them at all, so let's not do that. Instead, iterate over sensor DT nodes and only enable monitoring sites that are specified there prior to registering their thermal zones. This still fixes the issue with bogus data being reported on the first reading, but doesn't introduce problems that come with reading from non-existent sites.
Fixes: 45038e03d633 ("thermal: qoriq: Enable all sensors before registering them") Cc: stable@vger.kernel.org Signed-off-by: Sebastian Krzyszkowiak sebastian.krzyszkowiak@puri.sm --- v3: add cc: stable v2: augment the commit message with details on what the patch is doing --- drivers/thermal/qoriq_thermal.c | 63 ++++++++++++++++++++++----------- 1 file changed, 43 insertions(+), 20 deletions(-)
diff --git a/drivers/thermal/qoriq_thermal.c b/drivers/thermal/qoriq_thermal.c index 73049f9bea25..ef0848849ee2 100644 --- a/drivers/thermal/qoriq_thermal.c +++ b/drivers/thermal/qoriq_thermal.c @@ -32,7 +32,6 @@ #define TMR_DISABLE 0x0 #define TMR_ME 0x80000000 #define TMR_ALPF 0x0c000000 -#define TMR_MSITE_ALL GENMASK(15, 0)
#define REGS_TMTMIR 0x008 /* Temperature measurement interval Register */ #define TMTMIR_DEFAULT 0x0000000f @@ -129,33 +128,51 @@ static const struct thermal_zone_of_device_ops tmu_tz_ops = { static int qoriq_tmu_register_tmu_zone(struct device *dev, struct qoriq_tmu_data *qdata) { - int id; + int ret = 0; + struct device_node *np, *child, *sensor_np;
- if (qdata->ver == TMU_VER1) { - regmap_write(qdata->regmap, REGS_TMR, - TMR_MSITE_ALL | TMR_ME | TMR_ALPF); - } else { - regmap_write(qdata->regmap, REGS_V2_TMSR, TMR_MSITE_ALL); - regmap_write(qdata->regmap, REGS_TMR, TMR_ME | TMR_ALPF_V2); - } + np = of_find_node_by_name(NULL, "thermal-zones"); + if (!np) + return -ENODEV; + + sensor_np = of_node_get(dev->of_node);
- for (id = 0; id < SITES_MAX; id++) { + for_each_available_child_of_node(np, child) { struct thermal_zone_device *tzd; - struct qoriq_sensor *sensor = &qdata->sensor[id]; - int ret; + struct qoriq_sensor *sensor; + int id, site; + + ret = thermal_zone_of_get_sensor_id(child, sensor_np, &id); + + if (ret < 0) { + dev_err(dev, "failed to get valid sensor id: %d\n", ret); + of_node_put(child); + break; + }
+ sensor = &qdata->sensor[id]; sensor->id = id;
+ /* Enable monitoring */ + if (qdata->ver == TMU_VER1) { + site = 0x1 << (15 - id); + regmap_update_bits(qdata->regmap, REGS_TMR, + site | TMR_ME | TMR_ALPF, + site | TMR_ME | TMR_ALPF); + } else { + site = 0x1 << id; + regmap_update_bits(qdata->regmap, REGS_V2_TMSR, site, site); + regmap_write(qdata->regmap, REGS_TMR, TMR_ME | TMR_ALPF_V2); + } + tzd = devm_thermal_zone_of_sensor_register(dev, id, sensor, &tmu_tz_ops); - ret = PTR_ERR_OR_ZERO(tzd); - if (ret) { - if (ret == -ENODEV) - continue; - - regmap_write(qdata->regmap, REGS_TMR, TMR_DISABLE); - return ret; + if (IS_ERR(tzd)) { + ret = PTR_ERR(tzd); + dev_err(dev, "failed to register thermal zone: %d\n", ret); + of_node_put(child); + break; }
if (devm_thermal_add_hwmon_sysfs(tzd)) @@ -164,7 +181,13 @@ static int qoriq_tmu_register_tmu_zone(struct device *dev,
}
- return 0; + of_node_put(sensor_np); + of_node_put(np); + + if (ret) + regmap_write(qdata->regmap, REGS_TMR, TMR_DISABLE); + + return ret; }
static int qoriq_tmu_calibration(struct device *dev,