linux-kernel - [PATCH 2/2] Input: drv2667: Fix misuse of regmap_update

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Message-Id: <1480438754-14794-3-git-send-email-florian.vaussard@heig-vd.ch>
Date:   Tue, 29 Nov 2016 17:59:14 +0100
From:   Florian Vaussard <florian.vaussard@...il.com>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Dan Murphy <dmurphy@...com>, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Florian Vaussard <florian.vaussard@...g-vd.ch>
Subject: [PATCH 2/2] Input: drv2667: Fix misuse of regmap_update_bits

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@...g-vd.ch>
---
 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