[PATCH 5.10 83/99] Input: touchscreen - avoid bitwise vs logical OR warning

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Nathan Chancellor <nathan@xxxxxxxxxx>

commit a02dcde595f7cbd240ccd64de96034ad91cffc40 upstream.

A new warning in clang points out a few places in this driver where a
bitwise OR is being used with boolean types:

drivers/input/touchscreen.c:81:17: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
        data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-x",
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This use of a bitwise OR is intentional, as bitwise operations do not
short circuit, which allows all the calls to touchscreen_get_prop_u32()
to happen so that the last parameter is initialized while coalescing the
results of the calls to make a decision after they are all evaluated.

To make this clearer to the compiler, use the '|=' operator to assign
the result of each touchscreen_get_prop_u32() call to data_present,
which keeps the meaning of the code the same but makes it obvious that
every one of these calls is expected to happen.

Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211014205757.3474635-1-nathan@xxxxxxxxxx
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/input/touchscreen/of_touchscreen.c |   42 ++++++++++++++---------------
 1 file changed, 21 insertions(+), 21 deletions(-)

--- a/drivers/input/touchscreen/of_touchscreen.c
+++ b/drivers/input/touchscreen/of_touchscreen.c
@@ -79,27 +79,27 @@ void touchscreen_parse_properties(struct
 
 	data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-x",
 						input_abs_get_min(input, axis_x),
-						&minimum) |
-		       touchscreen_get_prop_u32(dev, "touchscreen-size-x",
-						input_abs_get_max(input,
-								  axis_x) + 1,
-						&maximum) |
-		       touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x",
-						input_abs_get_fuzz(input, axis_x),
-						&fuzz);
+						&minimum);
+	data_present |= touchscreen_get_prop_u32(dev, "touchscreen-size-x",
+						 input_abs_get_max(input,
+								   axis_x) + 1,
+						 &maximum);
+	data_present |= touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x",
+						 input_abs_get_fuzz(input, axis_x),
+						 &fuzz);
 	if (data_present)
 		touchscreen_set_params(input, axis_x, minimum, maximum - 1, fuzz);
 
 	data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-y",
 						input_abs_get_min(input, axis_y),
-						&minimum) |
-		       touchscreen_get_prop_u32(dev, "touchscreen-size-y",
-						input_abs_get_max(input,
-								  axis_y) + 1,
-						&maximum) |
-		       touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y",
-						input_abs_get_fuzz(input, axis_y),
-						&fuzz);
+						&minimum);
+	data_present |= touchscreen_get_prop_u32(dev, "touchscreen-size-y",
+						 input_abs_get_max(input,
+								   axis_y) + 1,
+						 &maximum);
+	data_present |= touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y",
+						 input_abs_get_fuzz(input, axis_y),
+						 &fuzz);
 	if (data_present)
 		touchscreen_set_params(input, axis_y, minimum, maximum - 1, fuzz);
 
@@ -107,11 +107,11 @@ void touchscreen_parse_properties(struct
 	data_present = touchscreen_get_prop_u32(dev,
 						"touchscreen-max-pressure",
 						input_abs_get_max(input, axis),
-						&maximum) |
-		       touchscreen_get_prop_u32(dev,
-						"touchscreen-fuzz-pressure",
-						input_abs_get_fuzz(input, axis),
-						&fuzz);
+						&maximum);
+	data_present |= touchscreen_get_prop_u32(dev,
+						 "touchscreen-fuzz-pressure",
+						 input_abs_get_fuzz(input, axis),
+						 &fuzz);
 	if (data_present)
 		touchscreen_set_params(input, axis, 0, maximum, fuzz);
 





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux