Re: [PATCH net-next v3 2/3] net: fsl: Allow most drivers to be built with COMPILE_TEST

On Wed, Nov 16, 2016 at 11:52:45AM -0800, Florian Fainelli wrote:

On 11/15/2016 07:23 PM, kbuild test robot wrote:

quoted

Hi Florian,

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Florian-Fainelli/net-gianfar_ptp-Rename-FS-bit-to-FIPERST/20161116-095805
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=sh

All warnings (new ones prefixed by >>):

   drivers/net/ethernet/freescale/fsl_pq_mdio.c: In function 'fsl_pq_mdio_remove':

quoted

quoted

drivers/net/ethernet/freescale/fsl_pq_mdio.c:498:27: warning: unused variable 'priv' [-Wunused-variable]

     struct fsl_pq_mdio_priv *priv = bus->priv;

Humm, this looks bogus, the variable is used see below:

quoted

                              ^~~~

vim +/priv +498 drivers/net/ethernet/freescale/fsl_pq_mdio.c

1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  482  	return 0;
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  483
dd3b8a32 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  484  error:
dd3b8a32 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  485  	if (priv->map)
b3319b10 drivers/net/fsl_pq_mdio.c                    Anton Vorontsov 2009-12-30  486  		iounmap(priv->map);
dd3b8a32 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  487
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  488  	kfree(new_bus);
dd3b8a32 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  489
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  490  	return err;
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  491  }
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  492
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  493
5078ac79 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  494  static int fsl_pq_mdio_remove(struct platform_device *pdev)
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  495  {
5078ac79 drivers/net/ethernet/freescale/fsl_pq_mdio.c Timur Tabi      2012-08-29  496  	struct device *device = &pdev->dev;
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  497  	struct mii_bus *bus = dev_get_drvdata(device);
b3319b10 drivers/net/fsl_pq_mdio.c                    Anton Vorontsov 2009-12-30 @498  	struct fsl_pq_mdio_priv *priv = bus->priv;
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  499
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  500  	mdiobus_unregister(bus);
1577ecef drivers/net/fsl_pq_mdio.c                    Andy Fleming    2009-02-04  501
b3319b10 drivers/net/fsl_pq_mdio.c                    Anton Vorontsov 2009-12-30  502  	iounmap(priv->map);

Right here.

What compiler version is this?

Compiler is sh4-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705.

include/asm-generic/io.h conditionally defines iounmap() to be an
empty inline function, which may explain the warning on sh4.

General speaking, it's a false warning. The solution could be to teach
the robot to ignore such 'unused variable' warnings in non-x86 archs.

Thanks,
Fengguang