On Thu, Nov 17, 2022 at 07:01:05PM +0100, Christian König wrote: > Am 17.11.22 um 18:32 schrieb Dmitry Osipenko: > > On 11/17/22 20:08, Lukasz Wiecaszek wrote: > > > On Thu, Nov 17, 2022 at 12:04:35PM +0300, Dmitry Osipenko wrote: > > > > Hi, > > > > > > > > On 11/17/22 07:58, Lukasz Wiecaszek wrote: > > > > > The reason behind that patch is associated with videobuf2 subsystem > > > > > (or more genrally with v4l2 framework) and user created > > > > > dma buffers (udmabuf). In some circumstances > > > > > when dealing with V4L2_MEMORY_DMABUF buffers videobuf2 subsystem > > > > > wants to use dma_buf_vmap() method on the attached dma buffer. > > > > > As udmabuf does not have .vmap operation implemented, > > > > > such dma_buf_vmap() natually fails. > > > > > > > > > > videobuf2_common: __vb2_queue_alloc: allocated 3 buffers, 1 plane(s) each > > > > > videobuf2_common: __prepare_dmabuf: buffer for plane 0 changed > > > > > videobuf2_common: __prepare_dmabuf: failed to map dmabuf for plane 0 > > > > > videobuf2_common: __buf_prepare: buffer preparation failed: -14 > > > > > > > > > > The patch itself seems to be strighforward. > > > > > It adds implementation of .vmap and .vunmap methods > > > > > to 'struct dma_buf_ops udmabuf_ops'. > > > > > .vmap method itself uses vm_map_ram() to map pages linearly > > > > > into the kernel virtual address space. > > > > > .vunmap removes mapping created earlier by .vmap. > > > > > All locking and 'vmapping counting' is done in dma_buf.c > > > > > so it seems to be redundant/unnecessary in .vmap/.vunmap. > > > > > > > > > > Signed-off-by: Lukasz Wiecaszek <lukasz.wiecaszek@xxxxxxxxx> > > > > If new patch version doesn't contain significant changes and you got > > > > acks/reviews for the previous version, then you should add the given > > > > acked-by and reviewed-by tags to the commit message by yourself. > > > > > > > > -- > > > > Best regards, > > > > Dmitry > > > > > > > I would like to thank you all for your patience and on the same time say > > > sorry that I still cannot follow the process (although I have read > > > 'submitting patches' chapter). > > If you'll continue to contribute actively, you'll find things that > > aren't documented at all. Don't worry about it, usually somebody will > > tell you about what's missing. Just apply the new knowledge next time ;) > > Yeah, it's more learning by doing. Especially I suspect you don't have > commit rights to drm-misc-next (or do you want to upstream it through some > other branch?), so as soon as nobody has any more objections ping Dmitry or > me to push this. > > Cheers, > Christian > > PS: The Signed-of-by, Reviewed-by, Acked-by etc... lines are usually added > in chronological order, e.g. your Signed-of-by line should always come > first. > > Thanks one more time. Funny thing, but at the very beginning I had Signed-of-by as the first line. Then I looked at 'git log' and spoted different order, so I change mine as well. Ahhh. But this chronological order of course make sense. So if you feel ok with this 'out of order' issue, please push/merge this commit. If not, please let me know. I already submitted version 5 of that work. So if change is required, I will prepare version 6.
