On Mon, 20 Dec 2021 at 11:59, Greg KH [off-list ref] wrote:

On Fri, Dec 17, 2021 at 03:41:19PM +0100, Anders Roxell wrote:

quoted

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 <redacted>
Reviewed-by: Nick Desaulniers <redacted>
Link: https://lore.kernel.org/r/20211014205757.3474635-1-nathan@kernel.org (local)
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Anders Roxell <redacted>
---
 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.

Yes I will, I'm sorry.

Cheers,
Anders

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