Thermal core tries to read temperature during sensor registering in
thermal_zone_of_sensor_register(). In that time Exynos TMU driver and
hardware are not yet initialized. Commit 0eb875d88aaa ("thermal:
exynos: Reading temperature makes sense only when TMU is turned on")
added a boolean flag to prevent reading bogus temperature in such
case but it exposed warning message during boot:
[ 3.864913] thermal thermal_zone0: failed to read out thermal zone
(-22)
Return EAGAIN in such case to skip omitting such message because it
might mislead user.
Signed-off-by: Krzysztof Kozlowski <k...@kernel.org>
---
drivers/thermal/samsung/exynos_tmu.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/samsung/exynos_tmu.c
b/drivers/thermal/samsung/exynos_tmu.c
index 3b20309789e3..c24969d740d1 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -666,8 +666,14 @@ static int exynos_get_temp(void *p, int *temp)
struct exynos_tmu_data *data = p;
int value, ret = 0;
- if (!data || !data->tmu_read || !data->enabled)
+ if (!data || !data->tmu_read)
return -EINVAL;
+ else if (!data->enabled)
+ /*
+ * Called too early, probably
+ * from thermal_zone_of_sensor_register().
+ */
+ return -EAGAIN;
mutex_lock(&data->lock);
clk_enable(data->clk);
--
2.14.1
