diff options
| author | Loic Prylli <lprylli@netflix.com> | 2023-11-03 11:30:55 +0100 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2024-02-04 06:43:44 -0800 |
| commit | 1168491e7f53581ba7b6014a39a49cfbbb722feb (patch) | |
| tree | c7a0358998ad5a6645ac7537cb0716e5929c5498 /drivers/hwmon | |
| parent | 54be6c6c5ae8e0d93a6c4641cb7528eb0b6ba478 (diff) | |
| download | linux-1168491e7f53581ba7b6014a39a49cfbbb722feb.tar.gz | |
hwmon: (aspeed-pwm-tacho) mutex for tach reading
the ASPEED_PTCR_RESULT Register can only hold the result for a
single fan input. Adding a mutex to protect the register until the
reading is done.
Signed-off-by: Loic Prylli <lprylli@netflix.com>
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
Fixes: 2d7a548a3eff ("drivers: hwmon: Support for ASPEED PWM/Fan tach")
Link: https://lore.kernel.org/r/121d888762a1232ef403cf35230ccf7b3887083a.1699007401.git.alexander.hansen@9elements.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/aspeed-pwm-tacho.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c index f6e1e55e82922..4acc1858d8acf 100644 --- a/drivers/hwmon/aspeed-pwm-tacho.c +++ b/drivers/hwmon/aspeed-pwm-tacho.c @@ -195,6 +195,8 @@ struct aspeed_pwm_tacho_data { u8 fan_tach_ch_source[MAX_ASPEED_FAN_TACH_CHANNELS]; struct aspeed_cooling_device *cdev[8]; const struct attribute_group *groups[3]; + /* protects access to shared ASPEED_PTCR_RESULT */ + struct mutex tach_lock; }; enum type { TYPEM, TYPEN, TYPEO }; @@ -529,6 +531,8 @@ static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv, u8 fan_tach_ch_source, type, mode, both; int ret; + mutex_lock(&priv->tach_lock); + regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0); regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0x1 << fan_tach_ch); @@ -546,6 +550,8 @@ static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv, ASPEED_RPM_STATUS_SLEEP_USEC, usec); + mutex_unlock(&priv->tach_lock); + /* return -ETIMEDOUT if we didn't get an answer. */ if (ret) return ret; @@ -915,6 +921,7 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev) priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; + mutex_init(&priv->tach_lock); priv->regmap = devm_regmap_init(dev, NULL, (__force void *)regs, &aspeed_pwm_tacho_regmap_config); if (IS_ERR(priv->regmap)) |