[PATCH] cxgb4: fix invalid checks in alloc_uld_rxqs

From: Andrzej Hajda
Date: Tue Aug 23 2016 - 02:16:40 EST


Local variable msi_idx defined as unsigned int is always >= 0, thus both
'if' checks are always true. On the other side presence of USING_MSIX flag
suggests the checks should not be trivially true.
The simplest solution is to replace incorrect checks with direct testing
of adap->flags and remove spare variables.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
---
Hi,

I am not familiar with the code, and it is not clear to me, so my solution
can be incorrect, anyway there is an issue here.

Regards
Andrzej
---
drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
index aac6e44..1e0c952 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
@@ -121,20 +121,14 @@ static int alloc_uld_rxqs(struct adapter *adap,
struct sge_uld_rxq_info *rxq_info,
unsigned int nq, unsigned int offset, bool lro)
{
- struct sge *s = &adap->sge;
struct sge_ofld_rxq *q = rxq_info->uldrxq + offset;
unsigned short *ids = rxq_info->rspq_id + offset;
unsigned int per_chan = nq / adap->params.nports;
- unsigned int msi_idx, bmap_idx;
+ unsigned int bmap_idx;
int i, err;

- if (adap->flags & USING_MSIX)
- msi_idx = 1;
- else
- msi_idx = -((int)s->intrq.abs_id + 1);
-
for (i = 0; i < nq; i++, q++) {
- if (msi_idx >= 0) {
+ if (adap->flags & USING_MSIX) {
bmap_idx = get_msix_idx_from_bmap(adap);
adap->msi_idx++;
}
@@ -147,7 +141,7 @@ static int alloc_uld_rxqs(struct adapter *adap,
0);
if (err)
goto freeout;
- if (msi_idx >= 0)
+ if (adap->flags & USING_MSIX)
rxq_info->msix_tbl[i + offset] = bmap_idx;
memset(&q->stats, 0, sizeof(q->stats));
if (ids)
--
1.9.1