Re: [PATCH 1/2] Input: drv2665: Fix misuse of regmap_update_bits

From: Dmitry Torokhov
Date: Tue Nov 29 2016 - 20:39:31 EST


On Tue, Nov 29, 2016 at 05:59:13PM +0100, Florian Vaussard wrote:
> Using regmap_update_bits(..., mask, 1) with 'mask' following (1 << k)
> and k greater than 0 is wrong. Indeed, _regmap_update_bits will perform
> (mask & 1), which results in 0 if LSB of mask is 0. Thus the call
> regmap_update_bits(..., mask, 1) is in reality equivalent to
> regmap_update_bits(..., mask, 0).
>
> In such a case, the correct use is regmap_update_bits(..., mask, mask).
>
> This driver is performing such a mistake with the DRV2665_STANDBY mask,
> which equals BIT(6). Fix the driver to make it consistent with the API,
> and fix the alignment problem at the same time. Please note that this
> change is untested, as I do not have this piece of hardware. Testers
> are welcome!
>
> Signed-off-by: Florian Vaussard <florian.vaussard@xxxxxxxxxx>

Applied, thank you.

> ---
> drivers/input/misc/drv2665.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/misc/drv2665.c b/drivers/input/misc/drv2665.c
> index ef9bc12..b0f46e7 100644
> --- a/drivers/input/misc/drv2665.c
> +++ b/drivers/input/misc/drv2665.c
> @@ -126,7 +126,8 @@ static void drv2665_close(struct input_dev *input)
> cancel_work_sync(&haptics->work);
>
> error = regmap_update_bits(haptics->regmap,
> - DRV2665_CTRL_2, DRV2665_STANDBY, 1);
> + DRV2665_CTRL_2, DRV2665_STANDBY,
> + DRV2665_STANDBY);
> if (error)
> dev_err(&haptics->client->dev,
> "Failed to enter standby mode: %d\n", error);
> @@ -240,7 +241,7 @@ static int __maybe_unused drv2665_suspend(struct device *dev)
>
> if (haptics->input_dev->users) {
> ret = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
> - DRV2665_STANDBY, 1);
> + DRV2665_STANDBY, DRV2665_STANDBY);
> if (ret) {
> dev_err(dev, "Failed to set standby mode\n");
> regulator_disable(haptics->regulator);
> --
> 2.5.5
>

--
Dmitry