| From a02dcde595f7cbd240ccd64de96034ad91cffc40 Mon Sep 17 00:00:00 2001 |
| From: Nathan Chancellor <nathan@kernel.org> |
| Date: Fri, 15 Oct 2021 13:13:06 -0700 |
| Subject: Input: touchscreen - avoid bitwise vs logical OR warning |
| |
| From: Nathan Chancellor <nathan@kernel.org> |
| |
| 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@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> |
| Signed-off-by: Anders Roxell <anders.roxell@linaro.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/input/touchscreen/of_touchscreen.c | 18 +++++++++--------- |
| 1 file changed, 9 insertions(+), 9 deletions(-) |
| |
| --- a/drivers/input/touchscreen/of_touchscreen.c |
| +++ b/drivers/input/touchscreen/of_touchscreen.c |
| @@ -79,8 +79,8 @@ void touchscreen_parse_properties(struct |
| data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-x", |
| input_abs_get_max(input, |
| axis) + 1, |
| - &maximum) | |
| - touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x", |
| + &maximum); |
| + data_present |= touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x", |
| input_abs_get_fuzz(input, axis), |
| &fuzz); |
| if (data_present) |
| @@ -90,8 +90,8 @@ void touchscreen_parse_properties(struct |
| data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-y", |
| input_abs_get_max(input, |
| axis) + 1, |
| - &maximum) | |
| - touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y", |
| + &maximum); |
| + data_present |= touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y", |
| input_abs_get_fuzz(input, axis), |
| &fuzz); |
| if (data_present) |
| @@ -101,11 +101,11 @@ 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, maximum, fuzz); |
| |
