On Thu, Jul 09, 2020 at 06:18:18AM -0700, Tom Rix wrote:
> I think a better change is to use the ret variable, like this
>
> --- a/drivers/fpga/dfl-pci.c
> +++ b/drivers/fpga/dfl-pci.c
> @@ -312,7 +312,7 @@ static int cci_pci_sriov_configure(struct pci_dev *pcidev, int num_vfs)
> }
> }
>
> - return num_vfs;
> + return ret;
> }
>
> The existing use of returning num_vfs is not right, the function should return 0/err not num_vfs. currently it is reusing the 0 passed in with num_vfs to mean disable as the 0 return status. it should be properly returning ret.
The sriov_configure callback should return negative value for error, and
return num_vfs if success.
See the Documentation/PCI/pci-iov-howto.rst
also in drivers/pci/iov.c:
static ssize_t sriov_numvfs_store(struct device *dev, ...)
{
...
ret = pdev->driver->sriov_configure(pdev, num_vfs);
if (ret < 0)
goto exit;
if (ret != num_vfs)
pci_warn(pdev, "%d VFs requested; only %d enabled\n",
num_vfs, ret);
...
}
>
> Tom
>
> On 7/9/20 1:12 AM, Xu Yilun wrote:
> > This is to fix lkp cppcheck warnings:
> >
> > drivers/fpga/dfl-pci.c:230:6: warning: The scope of the variable 'ret' can be reduced. [variableScope]
> > int ret = 0;
> > ^
> >
> > drivers/fpga/dfl-pci.c:230:10: warning: Variable 'ret' is assigned a value that is never used. [unreadVariable]
> > int ret = 0;
> > ^
> >
> > Fixes: 3c2760b78f90 ("fpga: dfl: pci: fix return value of cci_pci_sriov_configure")
> > Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> > Acked-by: Wu Hao <hao.wu@xxxxxxxxx>
> > ---
> > drivers/fpga/dfl-pci.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> > index 4a14a24..73b5153 100644
> > --- a/drivers/fpga/dfl-pci.c
> > +++ b/drivers/fpga/dfl-pci.c
> > @@ -285,7 +285,6 @@ static int cci_pci_sriov_configure(struct pci_dev *pcidev, int num_vfs)
> > {
> > struct cci_drvdata *drvdata = pci_get_drvdata(pcidev);
> > struct dfl_fpga_cdev *cdev = drvdata->cdev;
> > - int ret = 0;
> >
> > if (!num_vfs) {
> > /*
> > @@ -297,6 +296,8 @@ static int cci_pci_sriov_configure(struct pci_dev *pcidev, int num_vfs)
> > dfl_fpga_cdev_config_ports_pf(cdev);
> >
> > } else {
> > + int ret;
> > +
> > /*
> > * before enable SRIOV, put released ports into VF access mode
> > * first of all.
