[PATCH] [v2] Input: touchscreen: Fix a missing check on regmap_bulk_read

[PATCH] [v2] Input: touchscreen: Fix a missing check on regmap_bulk_read

[Aditya Pakki]

regmap_bulk_read() can return a non zero value on failure. The fix
checks if the function call succeeded before calling mod_timer. The
issue was identified by a static analysis tool.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
 drivers/input/touchscreen/ad7879.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index 6fa714c587b4..8c908572c1f2 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -246,11 +246,14 @@ static void ad7879_timer(struct timer_list *t)
 static irqreturn_t ad7879_irq(int irq, void *handle)
 {
 	struct ad7879 *ts = handle;
+	int error;
 
-	regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
-			 ts->conversion_data, AD7879_NR_SENSE);
-
-	if (!ad7879_report(ts))
+	error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
+					ts->conversion_data, AD7879_NR_SENSE);
+	if (error)
+		dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
+					AD7879_REG_XPLUS, error);
+	else if (!ad7879_report(ts))
 		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
 
 	return IRQ_HANDLED;
-- 
2.17.1

Re: [PATCH] [v2] Input: touchscreen: Fix a missing check on regmap_bulk_read

[Dmitry Torokhov]

On Sun, Jan 06, 2019 at 12:17:27PM -0600, Aditya Pakki wrote:
> regmap_bulk_read() can return a non zero value on failure. The fix
> checks if the function call succeeded before calling mod_timer. The
> issue was identified by a static analysis tool.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>

Applied, thank you.

> ---
>  drivers/input/touchscreen/ad7879.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
> index 6fa714c587b4..8c908572c1f2 100644
> --- a/drivers/input/touchscreen/ad7879.c
> +++ b/drivers/input/touchscreen/ad7879.c
> @@ -246,11 +246,14 @@ static void ad7879_timer(struct timer_list *t)
>  static irqreturn_t ad7879_irq(int irq, void *handle)
>  {
>  	struct ad7879 *ts = handle;
> +	int error;
>  
> -	regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
> -			 ts->conversion_data, AD7879_NR_SENSE);
> -
> -	if (!ad7879_report(ts))
> +	error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
> +					ts->conversion_data, AD7879_NR_SENSE);
> +	if (error)
> +		dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
> +					AD7879_REG_XPLUS, error);
> +	else if (!ad7879_report(ts))
>  		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
>  
>  	return IRQ_HANDLED;
> -- 
> 2.17.1
> 

-- 
Dmitry