On Mon, Apr 19, 2021 at 07:27:25PM +0800, Wan Jiabing wrote:>> struct device is declared at 133rd line. > The declaration here is unnecessary. Remove it. > > Signed-off-by: Wan Jiabing <wanjiabing(a)vivo.com&gt; > --- > include/linux/libnvdimm.h | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h > index 01f251b6e36c..89b69e645ac7 100644 > --- a/include/linux/libnvdimm.h > +++ b/include/linux/libnvdimm.h > @@ -141,7 +141,6 @@ static inline void __iomem *devm_nvdimm_ioremap(struct device *dev, > > struct nvdimm_bus; > struct module; > -struct device; > struct nd_blk_region; What is the coding style preference for pre-declarations like this? Should they be placed at the top of the file? The patch is reasonable but if the intent is to declare right before use for clarity, both devm_nvdimm_memremap() and nd_blk_region_desc() use struct device. So perhaps this duplicate is on purpose? Ira

> struct nd_blk_region_desc { > int (*enable)(struct nvdimm_bus *nvdimm_bus, struct device *dev); > -- > 2.25.1 >

Hi Ira, Ira Weiny <ira.weiny(a)intel.com&gt; writes: > On Mon, Apr 19, 2021 at 07:27:25PM +0800, Wan Jiabing wrote: >> struct device is declared at 133rd line. >> The declaration here is unnecessary. Remove it. >> >> Signed-off-by: Wan Jiabing <wanjiabing(a)vivo.com&gt; >> --- >> include/linux/libnvdimm.h | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h >> index 01f251b6e36c..89b69e645ac7 100644 >> --- a/include/linux/libnvdimm.h >> +++ b/include/linux/libnvdimm.h >> @@ -141,7 +141,6 @@ static inline void __iomem *devm_nvdimm_ioremap(struct device *dev, >> >> struct nvdimm_bus; >> struct module; >> -struct device; >> struct nd_blk_region; > > What is the coding style preference for pre-declarations like this? Should > they be placed at the top of the file? > > The patch is reasonable but if the intent is to declare right before use for > clarity, both devm_nvdimm_memremap() and nd_blk_region_desc() use struct > device. So perhaps this duplicate is on purpose? There are other struct device usage much later in the file, which doesn't have any pre-declarations for struct device. So I assume this might not be on purpose :-)

On a side note, types.h can also be removed, since it's already included in kernel.h.