From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net: mlxsw: avoid unused variable warnings Date: Wed, 23 Mar 2016 14:38:05 -0400 (EDT) Message-ID: <20160323.143805.310789862506977932.davem@davemloft.net> References: <1458751080-2044921-1-git-send-email-arnd@arndb.de> <20160323165111.GJ5250@lunn.ch> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: arnd@arndb.de, jiri@mellanox.com, idosch@mellanox.com, eladr@mellanox.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: andrew@lunn.ch Return-path: In-Reply-To: <20160323165111.GJ5250@lunn.ch> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Andrew Lunn Date: Wed, 23 Mar 2016 17:51:11 +0100 > On Wed, Mar 23, 2016 at 05:37:38PM +0100, Arnd Bergmann wrote: >> dev_dbg_ratelimited() is a macro that ignores its arguments when DEBUG is >> not set, which can lead to unused variable warnings: >> >> ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cqe_sdq_handle': >> ethernet/mellanox/mlxsw/pci.c:646:18: warning: unused variable 'pdev' [-Wunused-variable] >> ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cqe_rdq_handle': >> ethernet/mellanox/mlxsw/pci.c:671:18: warning: unused variable 'pdev' [-Wunused-variable] >> >> This changes the mlxsw driver to remove the local variables we get >> warnings for and instead pass the device directly into the API. > > Hi Arnd > > Would it not be better to fix the macro? > > I think the issue is that dev_dbg_ratelimited calls no_printk(), > without making use of dev. So how about: > > #define dev_dbg_ratelimited(dev, fmt, ...) \ > ({ \ > if (0) \ > dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ > }) > > This follows the pattern for other macros for when DEBUG is not defined. Yeah, this is probably a better way to fix this problem.