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| author | Arnd Bergmann <arnd@arndb.de> | 2015-01-13 22:59:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-02 10:11:25 -0800 |
| commit | f3e2d56dce47dbd0bb3f69f84741b439542fef37 (patch) | |
| tree | 00769d12d48a04dc7d1c4fdabdde44397b83e6bb | |
| parent | 5f9ba5b693ed6d639a3e6b47f4c6cd80e36f2547 (diff) | |
| download | linux-f3e2d56dce47dbd0bb3f69f84741b439542fef37.tar.gz linux-f3e2d56dce47dbd0bb3f69f84741b439542fef37.tar.xz | |
tty/isicom: fix big-endian compile warning
Building an arm allmodconfig kernel triggers a lengthy but harmless
warning in the isicom driver:
drvers/tty/isicom.c: In function 'isicom_send_break':
uapi/linux/swab.h:13:15: warning: integer overflow in expression [-Woverflow]
(((__u16)(x) & (__u16)0x00ffU) << 8) | \
^
uapi/linux/swab.h:107:2: note: in expansion of macro '___constant_swab16'
___constant_swab16(x) : \
^
uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16'
#define __cpu_to_le16(x) ((__force __le16)__swab16((x)))
^
linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16'
#define cpu_to_le16 __cpu_to_le16
^
include/asm/io.h:270:6: note: in expansion of macro 'cpu_to_le16'
cpu_to_le16(v),__io(p)); })
^
drivers/tty/isicom.c:1058:2: note: in expansion of macro 'outw'
outw((length & 0xff00), base);
^
Apparently, the problem is related to the fact that the value 0xff00,
when used as a 16-bit number, is negative and passed into bitwise
operands of the generic byte swapping code.
Marking the input argument as unsigned in both technically correct
and avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/isicom.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/isicom.c b/drivers/tty/isicom.c index 59ed783c4bcd..2054427992e0 100644 --- a/drivers/tty/isicom.c +++ b/drivers/tty/isicom.c @@ -1055,7 +1055,7 @@ static int isicom_send_break(struct tty_struct *tty, int length) outw(0x8000 | ((port->channel) << (card->shift_count)) | 0x3, base); outw((length & 0xff) << 8 | 0x00, base); - outw((length & 0xff00), base); + outw((length & 0xff00u), base); InterruptTheCard(base); unlock_card(card); |