Commit 2af47c10 authored Jun 19, 2019 by Arnd Bergmann Committed by Jens Axboe Jun 20, 2019

floppy: fix harmless clang build warning

clang warns about unusual code in floppy.c that looks like it
was intended to be a bit mask operation, checking for a specific
bit in the UDP->cmos variable (FLOPPY1_TYPE expands to '4' on
ARM):

drivers/block/floppy.c:3902:17: error: use of logical '&&' with constant operand [-Werror,-Wconstant-logical-operand]
        if (!UDP->cmos && FLOPPY1_TYPE)
                       ^  ~~~~~~~~~~~~
drivers/block/floppy.c:3902:17: note: use '&' for a bitwise operation
        if (!UDP->cmos && FLOPPY1_TYPE)

The check here is redundant anyway, if FLOPPY1_TYPE is zero, then
assigning it to a zero UDP->cmos field does not change anything,
so removing the extra check here has no effect other than shutting
up the warning.

On x86, this will no longer read a hardware register, as the
FLOPPY1_TYPE macro is not expanded if UDP->cmos is already
zero, but the result is the same.

Cc: Robert Elliott <elliott@hpe.com>
Cc: Keith Busch <kbusch@kernel.org>
Link: https://patchwork.kernel.org/patch/10851841/


Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent f9bc64a0

drivers/block/floppy.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3900,7 +3900,7 @@ static void __init config_types(void)
		if (!UDP->cmos)
		UDP->cmos = FLOPPY0_TYPE;
		drive = 1;
		if (!UDP->cmos && FLOPPY1_TYPE)
		if (!UDP->cmos)
		UDP->cmos = FLOPPY1_TYPE;

		/* FIXME: additional physical CMOS drive detection should go here */

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