Hi, On Mon, Aug 12, 2019 at 10:49:56AM +0800, Wu Hao wrote: > This patch makes init callback of sub features optional. With > this change, people don't need to prepare any empty init callback. > > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx> Acked-by: Moritz Fischer <mdf@xxxxxxxxxx> > --- > drivers/fpga/dfl.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index c0512af..96a2b82 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -271,11 +271,13 @@ static int dfl_feature_instance_init(struct platform_device *pdev, > struct dfl_feature *feature, > struct dfl_feature_driver *drv) > { > - int ret; > + int ret = 0; > > - ret = drv->ops->init(pdev, feature); > - if (ret) > - return ret; > + if (drv->ops->init) { > + ret = drv->ops->init(pdev, feature); > + if (ret) > + return ret; > + } > > feature->ops = drv->ops; You could swap it around maybe like so: int dfl_feature_instance_init() ... { feature->ops = drv->ops; if (drv->ops->init) return drv->ops->init(pdev, feature); return 0; } With the caveat that feature->ops gets always set ... Your call. Thanks, Moritz