From: Zev Weiss zev@bewilderbeest.net
commit f4e6960f4f16b1ca5da16cec7612ecc86402ac05 upstream.
Commit c3963bc0a0cf ("hwmon: (nct6775) Split core and platform driver") introduced a slight change in nct6775_suspend() in order to avoid an otherwise-needless symbol export for nct6775_update_device(), replacing a call to that function with a simple dev_get_drvdata() instead.
As it turns out, there is no guarantee that nct6775_update_device() is ever called prior to suspend. If this happens, the resume function ends up writing bad data into the various chip registers, which results in a crash shortly after resume.
To fix the problem, just add the symbol export and return to using nct6775_update_device() as was employed previously.
Reported-by: Zoltán Kővágó dirty.ice.hu@gmail.com Tested-by: Zoltán Kővágó dirty.ice.hu@gmail.com Fixes: c3963bc0a0cf ("hwmon: (nct6775) Split core and platform driver") Cc: stable@kernel.org Signed-off-by: Zev Weiss zev@bewilderbeest.net Link: https://lore.kernel.org/r/20220810052646.13825-1-zev@bewilderbeest.net [groeck: Updated description] Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hwmon/nct6775-core.c | 3 ++- drivers/hwmon/nct6775-platform.c | 2 +- drivers/hwmon/nct6775.h | 2 ++ 3 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c index 446964cbae4c..da9ec6983e13 100644 --- a/drivers/hwmon/nct6775-core.c +++ b/drivers/hwmon/nct6775-core.c @@ -1480,7 +1480,7 @@ static int nct6775_update_pwm_limits(struct device *dev) return 0; }
-static struct nct6775_data *nct6775_update_device(struct device *dev) +struct nct6775_data *nct6775_update_device(struct device *dev) { struct nct6775_data *data = dev_get_drvdata(dev); int i, j, err = 0; @@ -1615,6 +1615,7 @@ static struct nct6775_data *nct6775_update_device(struct device *dev) mutex_unlock(&data->update_lock); return err ? ERR_PTR(err) : data; } +EXPORT_SYMBOL_GPL(nct6775_update_device);
/* * Sysfs callback functions diff --git a/drivers/hwmon/nct6775-platform.c b/drivers/hwmon/nct6775-platform.c index ab30437221ce..41c97cfacfb8 100644 --- a/drivers/hwmon/nct6775-platform.c +++ b/drivers/hwmon/nct6775-platform.c @@ -359,7 +359,7 @@ static int __maybe_unused nct6775_suspend(struct device *dev) { int err; u16 tmp; - struct nct6775_data *data = dev_get_drvdata(dev); + struct nct6775_data *data = nct6775_update_device(dev);
if (IS_ERR(data)) return PTR_ERR(data); diff --git a/drivers/hwmon/nct6775.h b/drivers/hwmon/nct6775.h index 93f708148e65..be41848c3cd2 100644 --- a/drivers/hwmon/nct6775.h +++ b/drivers/hwmon/nct6775.h @@ -196,6 +196,8 @@ static inline int nct6775_write_value(struct nct6775_data *data, u16 reg, u16 va return regmap_write(data->regmap, reg, value); }
+struct nct6775_data *nct6775_update_device(struct device *dev); + bool nct6775_reg_is_word_sized(struct nct6775_data *data, u16 reg); int nct6775_probe(struct device *dev, struct nct6775_data *data, const struct regmap_config *regmapcfg);