From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin Ian King Subject: Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Date: Thu, 24 Aug 2017 09:54:03 +0100 Message-ID: References: <20170823153936.22857-1-colin.king@canonical.com> <58f312cc-5f24-83b6-d12d-c66e4fd4dad2@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org To: Aviad Krawczyk , netdev@vger.kernel.org Return-path: In-Reply-To: <58f312cc-5f24-83b6-d12d-c66e4fd4dad2@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 24/08/17 09:48, Aviad Krawczyk wrote: > On 8/23/2017 6:39 PM, Colin King wrote: >> From: Colin Ian King >> >> The comparison of hw_ioctxt.rx_buf_sz_idx == -1 is always false because >> rx_buf_sz_idx is a uint16_t. Fix this by explicitly casting -1 to uint16_t. >> >> Detected by CoverityScan, CID#1454559 ("Operands don't affect result") >> >> Signed-off-by: Colin Ian King >> --- >> drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c >> index 09dec6de8dd5..71e26070fb7f 100644 >> --- a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c >> +++ b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c >> @@ -352,7 +352,7 @@ static int set_hw_ioctxt(struct hinic_hwdev *hwdev, unsigned int rq_depth, >> } >> } >> >> - if (hw_ioctxt.rx_buf_sz_idx == -1) >> + if (hw_ioctxt.rx_buf_sz_idx == (uint16_t)-1) >> return -EINVAL; >> >> hw_ioctxt.sq_depth = ilog2(sq_depth); >> > > Many thanks, Colin. > I prefer to avoid casting when possible, what do you think about replacing the condition by: > > if (rx_buf_sz_table[i].sz != HINIC_RX_BUF_SZ) > return -EINVAL; > Does that work as expected when rx_buf_sz_table[i].sz == -1?