Re: [PATCH 1/2] i2c: designware: Add missing locks

From: Hans de Goede
Date: Thu Jan 20 2022 - 06:25:52 EST


Hi,

On 1/20/22 01:16, Jan Dabros wrote:
> All accesses to controller's registers should be protected on
> probe, disable and xfer paths. This is needed for i2c bus controllers
> that are shared with but not controller by kernel.
>
> Signed-off-by: Jan Dabros <jsd@xxxxxxxxxxxx>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>

Regards,

Hans


> ---
> drivers/i2c/busses/i2c-designware-common.c | 12 ++++++++++++
> drivers/i2c/busses/i2c-designware-master.c | 6 ++++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
> index bf2a4920638a..9f8574320eb2 100644
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -578,7 +578,12 @@ int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
> * Try to detect the FIFO depth if not set by interface driver,
> * the depth could be from 2 to 256 from HW spec.
> */
> + ret = i2c_dw_acquire_lock(dev);
> + if (ret)
> + return ret;
> +
> ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &param);
> + i2c_dw_release_lock(dev);
> if (ret)
> return ret;
>
> @@ -607,6 +612,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap)
> void i2c_dw_disable(struct dw_i2c_dev *dev)
> {
> u32 dummy;
> + int ret;
> +
> + ret = i2c_dw_acquire_lock(dev);
> + if (ret)
> + return;
>
> /* Disable controller */
> __i2c_dw_disable(dev);
> @@ -614,6 +624,8 @@ void i2c_dw_disable(struct dw_i2c_dev *dev)
> /* Disable all interrupts */
> regmap_write(dev->map, DW_IC_INTR_MASK, 0);
> regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
> +
> + i2c_dw_release_lock(dev);
> }
>
> void i2c_dw_disable_int(struct dw_i2c_dev *dev)
> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
> index 9177463c2cbb..1a4b23556db3 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -905,7 +905,13 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
> irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
> }
>
> + ret = i2c_dw_acquire_lock(dev);
> + if (ret)
> + return ret;
> +
> i2c_dw_disable_int(dev);
> + i2c_dw_release_lock(dev);
> +
> ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
> dev_name(dev->dev), dev);
> if (ret) {
>