Re: [PATCH v2 6/8] media: platform: amd: isp4 video node and buffers handling added

[Sultan Alsawaf <sultan@kerneltoast.com>]

On Mon, Aug 11, 2025 at 05:05:39PM +0800, Du, Bin wrote:
> > > [ old quotes trimmed out ]
> > 
> > Following up on this: there were several more issues hiding in the driver that
> > needed to be fixed unfortunately. I ended up making a lot of changes to fix all
> > of the buffer lifetime issues, and I created individual commits for this work
> > because it was getting hard to keep track of all the changes.
> > 
> > I think I'll have this completed tomorrow and will provide a link to my tree
> > with my commits. Hopefully your internal branch hasn't diverged too much from
> > this patchset submission, otherwise there may be some conflicts to resolve.
> > 
> > Sultan
> 
> Really appreciate your time and effort. Yes, big code changes happen in our
> internal branch to address upstream comments, but i believe your commits
> will be extremely valuable. We can check and test after fixing possbile
> conflict.

I've pushed my work here:

  https://github.com/kerneltoast/kernel_x86_laptop.git v6.16-drm-tip-isp4-for-amd

Please see my changes since commit 48d18b6e58c6dadbc79374773736924d2f532da5 on
that branch, up to commit 5cdacf4ff108d83869414a00465e7a612bcd04b1.

There are 29 patches:

Sultan Alsawaf (29):
      media: amd: isp4: Use amdgpu helper functions for ISP buffers
      media: amd: isp4: Remove -mpreferred-stack-boundary=4 cflag
      media: amd: isp4: Remove -DCONFIG_COMPAT from ccflags-y
      media: amd: isp4: Remove the myriad of redundant ccflags includes
      media: amd: isp4: Pass warning flags through cc-option
      media: amd: isp4: Clean up amd_capture-objs formatting
      media: amd: isp4: Don't set CONFIG_AMD_ISP4 to y by default
      media: amd: isp4: Clean up AMD_ISP4 Kconfig dependencies
      media: amd: Fix Kconfig/Makefile directory structure
      media: amd: isp4: Remove superfluous NULL pointer checks
      media: amd: isp4: Remove superfluous void pointer casts
      media: amd: isp4: Remove superfluous memset in isp4vid_vb2_map_dmabuf()
      media: amd: isp4: Don't read refcount counter directly
      media: amd: isp4: Add missing refcount tracking to mmap memop
      media: amd: isp4: Don't put or unmap the dmabuf when detaching
      media: amd: isp4: Don't increment refcount when dmabuf export fails
      media: amd: isp4: Fix possible use-after-free in isp4vid_vb2_put()
      media: amd: isp4: Always export a new dmabuf from get_dmabuf memop
      media: amd: isp4: Fix implicit dmabuf lifetime tracking
      media: amd: isp4: Fix possible use-after-free when putting implicit dmabuf
      media: amd: isp4: Remove 'refcount > 0' warning in isp4vid_vb2_put()
      media: amd: isp4: Fix comment in isp4vid_vb2_dmabuf_ops_release()
      media: amd: isp4: Simplify isp4vid_get_dmabuf() arguments
      media: amd: isp4: Add comment to CONFIG_HAS_DMA #endif
      media: amd: isp4: Move up buf->vaddr check in isp4vid_get_dmabuf()
      media: amd: isp4: Remove unused userptr memops
      media: amd: isp4: Make isp4vid_vb2_memops static
      media: amd: isp4: Add missing cleanup on error in isp4vid_vb2_alloc()
      media: amd: isp4: Release queued buffers on error in start_streaming

 drivers/media/platform/amd/Kconfig               |  18 +-
 drivers/media/platform/amd/Makefile              |   6 +-
 drivers/media/platform/amd/isp4/Kconfig          |  14 ++
 drivers/media/platform/amd/isp4/Makefile         |  42 +---
 drivers/media/platform/amd/isp4/isp4.c           |   9 +-
 drivers/media/platform/amd/isp4/isp4.h           |  11 -
 drivers/media/platform/amd/isp4/isp4_debug.c     |   4 +-
 drivers/media/platform/amd/isp4/isp4_interface.c |  46 +---
 drivers/media/platform/amd/isp4/isp4_interface.h |   6 +-
 drivers/media/platform/amd/isp4/isp4_subdev.c    |   8 +-
 drivers/media/platform/amd/isp4/isp4_subdev.h    |   4 +-
 drivers/media/platform/amd/isp4/isp4_video.c     | 297 ++++++-----------------
 drivers/media/platform/amd/isp4/isp4_video.h     |   4 +-
 13 files changed, 122 insertions(+), 347 deletions(-)

At least 1 of them should be redundant for your internal branch (9f394a7af2cf
"media: amd: isp4: Use amdgpu helper functions for ISP buffers").

Cheers,
Sultan