6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Armin Wolf <W_Armin@xxxxxx>
[ Upstream commit 7da8a635436029957c5350da3acf51d78ed64071 ]
When the lock bit inside SCH5627_REG_CTRL is set, then the virtual
registers become read-only until the next power cycle.
Disallow write access to those registers in such a case.
Tested on a Fujitsu Esprimo P720.
Fixes: aa9f833dfc12 ("hwmon: (sch5627) Add pwmX_auto_channels_temp support")
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Link: https://lore.kernel.org/r/20230907052639.16491-3-W_Armin@xxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hwmon/sch5627.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/hwmon/sch5627.c b/drivers/hwmon/sch5627.c
index 0eefb8c0aef25..bf408e35e2c32 100644
--- a/drivers/hwmon/sch5627.c
+++ b/drivers/hwmon/sch5627.c
@@ -34,6 +34,7 @@
#define SCH5627_REG_CTRL 0x40
#define SCH5627_CTRL_START BIT(0)
+#define SCH5627_CTRL_LOCK BIT(1)
#define SCH5627_CTRL_VBAT BIT(4)
#define SCH5627_NO_TEMPS 8
@@ -231,6 +232,14 @@ static int reg_to_rpm(u16 reg)
static umode_t sch5627_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
int channel)
{
+ const struct sch5627_data *data = drvdata;
+
+ /* Once the lock bit is set, the virtual registers become read-only
+ * until the next power cycle.
+ */
+ if (data->control & SCH5627_CTRL_LOCK)
+ return 0444;
+
if (type == hwmon_pwm && attr == hwmon_pwm_auto_channels_temp)
return 0644;
--
2.42.0
