I2C core ensures in i2c_smbus_xfer() that the I2C bus lock is held when calling the smbus_xfer callback. That's i801_access() in our case. I think it's safe in general to assume that the I2C bus lock is held when the smbus_xfer callback is called. Therefore I see no need to define an own mutex. Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> --- Patch was part of a broken-up previous series. --- drivers/i2c/busses/i2c-i801.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 26f132277..a485dc84d 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -293,10 +293,9 @@ struct i801_priv { /* * If set to true the host controller registers are reserved for - * ACPI AML use. Protected by acpi_lock. + * ACPI AML use. */ bool acpi_reserved; - struct mutex acpi_lock; }; #define FEATURE_SMBUS_PEC BIT(0) @@ -874,11 +873,8 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, int hwpec, ret; struct i801_priv *priv = i2c_get_adapdata(adap); - mutex_lock(&priv->acpi_lock); - if (priv->acpi_reserved) { - mutex_unlock(&priv->acpi_lock); + if (priv->acpi_reserved) return -EBUSY; - } pm_runtime_get_sync(&priv->pci_dev->dev); @@ -919,7 +915,6 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, pm_runtime_mark_last_busy(&priv->pci_dev->dev); pm_runtime_put_autosuspend(&priv->pci_dev->dev); - mutex_unlock(&priv->acpi_lock); return ret; } @@ -1571,7 +1566,7 @@ i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, * further access from the driver itself. This device is now owned * by the system firmware. */ - mutex_lock(&priv->acpi_lock); + i2c_lock_bus(&priv->adapter, I2C_LOCK_SEGMENT); if (!priv->acpi_reserved && i801_acpi_is_smbus_ioport(priv, address)) { priv->acpi_reserved = true; @@ -1591,7 +1586,7 @@ i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, else status = acpi_os_write_port(address, (u32)*value, bits); - mutex_unlock(&priv->acpi_lock); + i2c_unlock_bus(&priv->adapter, I2C_LOCK_SEGMENT); return status; } @@ -1651,7 +1646,6 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) priv->adapter.dev.parent = &dev->dev; ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&dev->dev)); priv->adapter.retries = 3; - mutex_init(&priv->acpi_lock); priv->pci_dev = dev; priv->features = id->driver_data; -- 2.42.0