From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753503AbbKLVEZ (ORCPT ); Thu, 12 Nov 2015 16:04:25 -0500 Received: from mout.kundenserver.de ([212.227.126.133]:56883 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbbKLVEY (ORCPT ); Thu, 12 Nov 2015 16:04:24 -0500 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: David Miller , netdev@vger.kernel.org, mathieu@codeaurora.org, linux-kernel@vger.kernel.org, peppe.cavallaro@st.com Subject: [PATCH v2] stmmac: avoid ipq806x constant overflow warning Date: Thu, 12 Nov 2015 22:03:40 +0100 Message-ID: <3825178.3luTQFAgny@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <3729464.5X0HBxzvx5@wuerfel> References: <4391788.dtYArQ4mVi@wuerfel> <20151112.122528.1794206832971213176.davem@davemloft.net> <3729464.5X0HBxzvx5@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:5cXlapenx8KObccIyULE3UrxxmhIYw4qU207Zg1KbkRtYOqzXEh K2E24nfXSK+dzZmnpvDogBaWMpc6JKBuk85bxwg1lqkM4y1c1EGfDOBi4PeXmq5KsVTtTzu dj9QVNw5yImAjkWoFm1RbX0xPeuOXvNz3pKP4UDYX+Tb0fKrs8SJGjc+xKaY/6UzdBDu44N atUgC6s5S4nA/dnytosCQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:8IAYIRp4zBo=:T0oeoUrzDc1mQNwccTk5oH XI8QZdon1P5NWpbwjTxVwTnNEeFGY45qomhfha2UdXl8MBCBi20UqwwwRkzNoo+6WS11JZhtu 6yHYL3rAdeR5673KCYI9heh5Dp3vpow9nax6RcjcVpIqXTJk8fz0bKSHvAWXbXU8jZ0KDAEvX 4m/wbX/rojDmK6Wbe39kcxpFtEayI/N2bAtuuddsilY0z8ivYC8z4hmixiNb7137kw+WH3FFl YCLbR97ikfg9e5cRxtnPbvk5XmKc1jkVGDdSLgWBVQHZsvYqscbmm1dgEUoqxOYbZ6esdviH/ Sx090/or6wQOZGAMvqZa1sRjfmUB9DFWBnGA9Zucb7+GZsl5IWu/saxCditQyEu2ufDFwcql6 PmyZc5GBzfOf8Bd4JuA3yQMDpZDk7hBe2fB5lqlCORAAZY9kHHjpx0arGT/9H+6dFud35vhi0 +TxwRFwsN3x9YYHncS5wPmUSBd6BTHzVBiRNhmemawYyuVweSaa5du3lNY2kQHY9YtzgAFDau tP7DXLB9w5TRNI/3wpvz0hHwKB3CrtQHGRz0Y5YB41ylsYz5Bcduw0kBp2uYGtS4hrWGXLgv/ AMvvGpKCMbzwTOdjj13/uQQIagzwQA/hJkrcFJ0cSodNTTfrmbxsTRAZ5jf8HVeLzPKwein+/ ZNZxICFQU4lQkUwFu+s5u44hxFRu4m2MpJxjUpXfkv6gMpgq4Kwx79oBa0m5gEUxmNxxmjXwL tQAQSFGfvHDaoSNl Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Building dwmac-ipq806x on a 64-bit architecture produces a harmless warning from gcc: stmmac/dwmac-ipq806x.c: In function 'ipq806x_gmac_probe': include/linux/bitops.h:6:19: warning: overflow in implicit constant conversion [-Woverflow] val = QSGMII_PHY_CDR_EN | stmmac/dwmac-ipq806x.c:333:8: note: in expansion of macro 'QSGMII_PHY_CDR_EN' #define QSGMII_PHY_CDR_EN BIT(0) #define BIT(nr) (1UL << (nr)) This is a result of the type conversion rules in C, when we take the logical OR of multiple different types. In particular, we have and unsigned long QSGMII_PHY_CDR_EN == BIT(0) == (1ul << 0) == 0x0000000000000001ul and a signed int 0xC << QSGMII_PHY_TX_DRV_AMP_OFFSET == 0xc0000000 which together gives a signed long value 0xffffffffc0000001l and when this is passed into a function that takes an unsigned int type, gcc warns about the signed overflow and the loss of the upper 32-bits that are all ones. This patch adds 'ul' type modifiers to the literal numbers passed in here, so now the expression remains an 'unsigned long' with the upper bits all zero, and that avoids the signed overflow and the warning. Signed-off-by: Arnd Bergmann Fixes: b1c17215d718 ("stmmac: add ipq806x glue layer") diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c index 9d89bdbf029f..82de68b1a452 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c @@ -337,11 +337,11 @@ static int ipq806x_gmac_probe(struct platform_device *pdev) QSGMII_PHY_RX_SIGNAL_DETECT_EN | QSGMII_PHY_TX_DRIVER_EN | QSGMII_PHY_QSGMII_EN | - 0x4 << QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET | - 0x3 << QSGMII_PHY_RX_DC_BIAS_OFFSET | - 0x1 << QSGMII_PHY_RX_INPUT_EQU_OFFSET | - 0x2 << QSGMII_PHY_CDR_PI_SLEW_OFFSET | - 0xC << QSGMII_PHY_TX_DRV_AMP_OFFSET); + 0x4ul << QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET | + 0x3ul << QSGMII_PHY_RX_DC_BIAS_OFFSET | + 0x1ul << QSGMII_PHY_RX_INPUT_EQU_OFFSET | + 0x2ul << QSGMII_PHY_CDR_PI_SLEW_OFFSET | + 0xCul << QSGMII_PHY_TX_DRV_AMP_OFFSET); } plat_dat->has_gmac = true;