Messages in this thread | | | Date | Mon, 20 Dec 2021 11:59:34 +0100 | From | Greg KH <> | Subject | Re: [PATCH 4.19 6/6] Input: touchscreen - avoid bitwise vs logical OR warning |
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On Fri, Dec 17, 2021 at 03:41:19PM +0100, Anders Roxell wrote: > 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> > --- > drivers/input/touchscreen/of_touchscreen.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-)
Also needed in 5.10.y and 5.4.y.
Please be more careful next time.
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