Re: [PATCH 2/2] Input: drv2667: Fix misuse of regmap_update_bits

From: Dmitry Torokhov
Date: Tue Nov 29 2016 - 20:39:54 EST


On Tue, Nov 29, 2016 at 05:59:14PM +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 DRV2667_STANDBY mask,
> which equals (1 << 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/drv2667.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/misc/drv2667.c b/drivers/input/misc/drv2667.c
> index d5ba748..2849bb6 100644
> --- a/drivers/input/misc/drv2667.c
> +++ b/drivers/input/misc/drv2667.c
> @@ -256,7 +256,7 @@ static void drv2667_close(struct input_dev *input)
> cancel_work_sync(&haptics->work);
>
> error = regmap_update_bits(haptics->regmap, DRV2667_CTRL_2,
> - DRV2667_STANDBY, 1);
> + DRV2667_STANDBY, DRV2667_STANDBY);
> if (error)
> dev_err(&haptics->client->dev,
> "Failed to enter standby mode: %d\n", error);
> @@ -415,7 +415,7 @@ static int __maybe_unused drv2667_suspend(struct device *dev)
>
> if (haptics->input_dev->users) {
> ret = regmap_update_bits(haptics->regmap, DRV2667_CTRL_2,
> - DRV2667_STANDBY, 1);
> + DRV2667_STANDBY, DRV2667_STANDBY);
> if (ret) {
> dev_err(dev, "Failed to set standby mode\n");
> regulator_disable(haptics->regulator);
> --
> 2.5.5
>

--
Dmitry