On 02-03-20, 13:53, Peter Ujfalusi wrote: > > > On 02/03/2020 12.28, Peter Ujfalusi wrote: > > Hi Vinod, > > > > On 02/03/2020 9.11, Vinod Koul wrote: > >>> diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h > >>> index e8a320c9e57c..72cd7fe33638 100644 > >>> --- a/drivers/dma/dmaengine.h > >>> +++ b/drivers/dma/dmaengine.h > >>> @@ -182,4 +182,10 @@ dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb) > >>> struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); > >>> struct dma_chan *dma_get_any_slave_channel(struct dma_device *device); > >>> > >>> +#ifdef CONFIG_DEBUG_FS > >>> +#include <linux/debugfs.h> > >>> + > >>> +struct dentry *dmaengine_get_debugfs_root(void); > >> > >> this needs to have an else defined with NULL return so that we dont > >> force users to wrap the code under CONFIG_DEBUG_FS.. > > > > Drivers would anyways should have their debugfs related code wrapped > > within ifdef. There is no point of having the code complied when it can > > not be used (no debugfs support). > > > > But I can add the else case if we really want to: > > > > #ifdef CONFIG_DEBUG_FS > > #include <linux/debugfs.h> > > > > struct dentry *dmaengine_get_debugfs_root(void); > > > > #else > > struct dentry; > > static inline struct dentry *dmaengine_get_debugfs_root(void) > > { > > return NULL; > > } > > #endif /* CONFIG_DEBUG_FS */ > > It might be even better if the core creates directories for the dma > controllers in dma_async_device_register() and removes the whole > directory in dma_async_device_unregister() hmmm, i think makes sense and dentry can be part of dma_device > > Then drivers can get their per device root via: > #ifdef CONFIG_DEBUG_FS > static inline struct dentry * > dmaengine_get_debugfs_root(struct dma_device *dma_dev) { > return dma_dev->dbg_dev_root; > } right! > #else > struct dentry; > static inline struct dentry * > dmaengine_get_debugfs_root(struct dma_device *dma_dev) > { > return NULL; > } > #endif /* CONFIG_DEBUG_FS */ -- ~Vinod