Hello Frank,
On Fri, Dec 13, 2024 at 05:23:09PM -0500, Frank Li wrote:
> From: Luwei Zhou <b45643@xxxxxxxxxxxxx>
>
> Prevent continuous polling error logs by adding a chip ID check in the
> probe function. This ensures the driver only proceeds when the mma8450 is
> present, avoiding issues in scenarios like missing add-on cards.
>
> Signed-off-by: Luwei Zhou <b45643@xxxxxxxxxxxxx>
> Signed-off-by: Fugang Duan <B38611@xxxxxxxxxxxxx>
> Signed-off-by: Vipul Kumar <vipul_kumar@xxxxxxxxxx>
> Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> drivers/input/misc/mma8450.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c
> index 08412239b8e69..da941748ed29b 100644
> --- a/drivers/input/misc/mma8450.c
> +++ b/drivers/input/misc/mma8450.c
> @@ -38,6 +38,8 @@
>
> #define MMA8450_CTRL_REG1 0x38
> #define MMA8450_CTRL_REG2 0x39
> +#define MMA8450_ID 0xc6
> +#define MMA8450_WHO_AM_I 0x0f
>
> static int mma8450_read(struct i2c_client *c, unsigned int off)
> {
> @@ -148,8 +150,20 @@ static void mma8450_close(struct input_dev *input)
> */
> static int mma8450_probe(struct i2c_client *c)
> {
> + struct i2c_adapter *adapter = to_i2c_adapter(c->dev.parent);
+ struct i2c_adapter *adapter = c->adapter;
> struct input_dev *input;
> - int err;
> + int err, client_id;
> +
> + err = i2c_check_functionality(adapter,
> + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA);
> + if (!err)
> + return err;
How unusual. I would have expected no ! here.
> + client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I);
> + if (client_id != MMA8450_ID)
> + return dev_err_probe(&c->dev, -EINVAL,
> + "read chip ID 0x%x is not equal to 0x%x!\n",
> + client_id, MMA8450_ID);
Given that here you emit an error message, maybe add an error message
above, too?
> input = devm_input_allocate_device(&c->dev);
> if (!input)
Best regards
Uwe
Attachment:
signature.asc
Description: PGP signature
