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authorArnd Bergmann <arnd@arndb.de>2015-01-14 00:59:47 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-02-02 21:11:25 +0300
commitf3e2d56dce47dbd0bb3f69f84741b439542fef37 (patch)
tree00769d12d48a04dc7d1c4fdabdde44397b83e6bb /drivers/tty/isicom.c
parent5f9ba5b693ed6d639a3e6b47f4c6cd80e36f2547 (diff)
downloadlinux-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>
Diffstat (limited to 'drivers/tty/isicom.c')
-rw-r--r--drivers/tty/isicom.c2
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);