> From: gregkh@xxxxxxxxxxxxxxxxxxx <gregkh@xxxxxxxxxxxxxxxxxxx> > Sent: Thursday, October 8, 2020 1:21 PM > > On Thu, Oct 08, 2020 at 12:38:00AM -0700, Dan Williams wrote: > > On Thu, Oct 8, 2020 at 12:01 AM Leon Romanovsky <leon@xxxxxxxxxx> > wrote: > > [..] > > > All stated above is my opinion, it can be different from yours. > > > > Yes, but we need to converge to move this forward. Jason was involved > > in the current organization for registration, Greg was angling for > > this to be core functionality. I have use cases outside of RDMA and > > netdev. Parav was ok with the current organization. The SOF folks > > already have a proposed incorporation of it. The argument I am hearing > > is that "this registration api seems hard for driver writers" when we > > have several driver writers who have already taken a look and can make > > it work. If you want to follow on with a simpler wrappers for your use > > case, great, but I do not yet see anyone concurring with your opinion > > that the current organization is irretrievably broken or too obscure > > to use. > > That's kind of because I tuned out of this thread a long time ago :) > > I do agree with Leon that I think the current patch is not the correct way to > do this the easiest, but don't have a competing proposal to show what I > mean. > > Yet. Please consider the approach of ib_alloc_device(), ib_dealloc_device() and ib_register_register()/unregister(). (a) It avoids driver calling put_device() on error unwinding path. (b) still achieves container_of(). > > Let's see what happens after 5.10-rc1 is out, it's too late now for any of this > for this next merge window so we can not worry about it for a few weeks. > Ok. INHO giving direction to Dave and others to either refine current APIs or follow ib_alloc_device() approach will be a helpful input. ancillary bus can do better APIs than the newly (march 2020 !) introduced vdpa bus [1] and its drivers which follows put_device() pattern in [2] and [3] in error unwinding path. [1] https://elixir.bootlin.com/linux/v5.9-rc8/source/drivers/vdpa/vdpa.c [2] https://elixir.bootlin.com/linux/v5.9-rc8/source/drivers/vdpa/ifcvf/ifcvf_main.c#L475 [3] https://elixir.bootlin.com/linux/v5.9-rc8/source/drivers/vdpa/mlx5/net/mlx5_vnet.c#L1967 > thanks, > > greg k-h
