[PATCH 6.1 22/64] hwmon: (aspeed-pwm-tacho) mutex for tach reading
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2024-02-13 17:23:40
Also in:
stable
Subsystem:
hardware monitoring, the rest · Maintainers:
Guenter Roeck, Linus Torvalds
6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Loic Prylli <redacted>
[ Upstream commit 1168491e7f53581ba7b6014a39a49cfbbb722feb ]
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 <redacted>
Signed-off-by: Alexander Hansen <redacted>
Fixes: 2d7a548a3eff ("drivers: hwmon: Support for ASPEED PWM/Fan tach")
Link: https://lore.kernel.org/r/121d888762a1232ef403cf35230ccf7b3887083a.1699007401.git.alexander.hansen@9elements.com (local)
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/aspeed-pwm-tacho.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index d11f674e3dc3..51f321bcd778 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c@@ -194,6 +194,8 @@ struct aspeed_pwm_tacho_data { u8 fan_tach_ch_source[16]; 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 };
@@ -528,6 +530,8 @@ 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);
@@ -545,6 +549,8 @@ 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;
@@ -904,6 +910,7 @@ 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))
--
2.43.0