[PATCH 2/2] drivers/s390/cio/chsc_sch.c: Correct use of ! and &

From: Julia Lawall
Date: Sat Oct 04 2008 - 16:06:03 EST


From: Julia Lawall <julia@xxxxxxx>

In commit e6bafba5b4765a5a252f1b8d31cbf6d2459da337, a bug was fixed that
involved converting !x & y to !(x & y). The code below shows the same
pattern, and thus should perhaps be fixed in the same way. In particular,
the result of !scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND is
always just !scsw_stctl(&request->irb.scsw).

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@ expression E; constant C; @@
(
!E & !C
|
- !E & C
+ !(E & C)
)
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/s390/cio/chsc_sch.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff -u -p a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -261,7 +261,7 @@ static int chsc_examine_irb(struct chsc_
{
int backed_up;

- if (!scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND)
+ if (!(scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND))
return -EIO;
backed_up = scsw_cstat(&request->irb.scsw) & SCHN_STAT_CHAIN_CHECK;
request->irb.scsw.cmd.cstat &= ~SCHN_STAT_CHAIN_CHECK;
--
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