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Input: touchscreen - avoid bitwise vs logical OR warning 

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@kernel.org>
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20211014205757.3474635-1-nathan@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Nathan Chancellor 2021-10-15 13:13:06 -07:00 committed by Dmitry Torokhov
parent 3378a07daa
commit a02dcde595
1 changed files with 21 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/input/touchscreen.c
View File

@ -80,27 +80,27 @@ void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
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);
@ -108,11 +108,11 @@ void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
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);