Input: ad7879 - add check for read errors in interrupt

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>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index 6fa714c..3a016f4 100644 (file)
--- 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;