Hello Martin, On Tue, Jan 23, 2018 at 08:30:41AM -0500, Martin K. Petersen wrote: > > Ming, > > > + * Block layer and block driver specific status, which is ususally returnd > ^^^^^^^ > > + * from driver to block layer in IO path. > > Given that the comment blurb is long and the flag not defined until > later, it is not entirely obvious that you are documenting > BLK_STS_DEV_RESOURCE. So please make that clear at the beginning of the > comment. OK, how about the following document? /* * BLK_STS_DEV_RESOURC: Block layer and block driver specific status, * which is usually returned from driver to block layer in IO path. * * BLK_STS_DEV_RESOURCE is returned from driver to block layer if device * related resource is run out of, but driver can guarantee that queue * will be rerun in future for dispatching the current request when this * resource is available. * * Difference with BLK_STS_RESOURCE: * If driver isn't sure if the queue can be run again for dealing with the * current request after this kind of resource is available, please return * BLK_STS_SOURCE, for example, when memory allocation, DMA Mapping or other * system resource allocation fails and IO can't be submitted to device, * BLK_STS_RESOURCE should be used for avoiding IO hang. */ #define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13) Thanks, Ming
