Merge tag 'drm-fixes-2021-03-12-1' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
 "Regular fixes for rc3. The i915 pull was based on the rc1 tag so I
  just cherry-picked the single fix from there to avoid it. The misc and
  amd trees seem to be on okay bases.

  It's a bunch of fixes across the tree, amdgpu has most of them a few
  ttm fixes around qxl, and nouveau.

  core:
   - Clear holes when converting compat ioctl's between 32-bits and
     64-bits.

  docs:
   - Use gitlab for drm bugzilla now.

  ttm:
   - Fix ttm page pool accounting.

  fbdev:
   - Fix oops in drm_fbdev_cleanup()

  shmem:
   - Assorted fixes for shmem helpers.

  qxl:
   - unpin qxl bos created as pinned when freeing them, and make ttm
     only warn once on this behavior.
   - Zero head.surface_id correctly in qxl.

  atyfb:
   - Use LCD management for atyfb on PPC_MAC.

  meson:
   - Shutdown kms poll helper in meson correctly.

  nouveau:
   - fix regression in bo syncing

  i915:
   - Wedge the GPU if command parser setup fails

  amdgpu:
   - Fix aux backlight control
   - Add a backlight override parameter
   - Various display fixes
   - PCIe DPM fix for vega
   - Polaris watermark fixes
   - Additional S0ix fix

  radeon:
   - Fix GEM regression
   - Fix AGP dependency handling"

* tag 'drm-fixes-2021-03-12-1' of git://anongit.freedesktop.org/drm/drm: (33 commits)
  drm/nouveau: fix dma syncing for loops (v2)
  drm/i915: Wedge the GPU if command parser setup fails
  drm/compat: Clear bounce structures
  drm/shmem-helpers: vunmap: Don't put pages for dma-buf
  drm: meson_drv add shutdown function
  drm/shmem-helper: Don't remove the offset in vm_area_struct pgoff
  drm/shmem-helper: Check for purged buffers in fault handler
  qxl: Fix uninitialised struct field head.surface_id
  drm/ttm: Fix TTM page pool accounting
  drm/ttm: soften TTM warnings
  drm: Use USB controller's DMA mask when importing dmabufs
  MAINTAINERS: update drm bug reporting URL
  fbdev: atyfb: use LCD management functions for PPC_PMAC also
  fbdev: atyfb: always declare aty_{ld,st}_lcd()
  drm/qxl: fix lockdep issue in qxl_alloc_release_reserved
  drm/qxl: unpin release objects
  drm/fb-helper: only unmap if buffer not null
  drm/amdgpu: fix S0ix handling when the CONFIG_AMD_PMC=m
  drm/radeon: fix AGP dependency
  drm/radeon: also init GEM funcs in radeon_gem_prime_import_sg_table
  ...

Documentation/gpu/todo.rst

@@ -613,6 +613,27 @@ Some of these date from the very introduction of KMS in 2008 ...
 
 Level: Intermediate
 
+Remove automatic page mapping from dma-buf importing
+----------------------------------------------------
+
+When importing dma-bufs, the dma-buf and PRIME frameworks automatically map
+imported pages into the importer's DMA area. drm_gem_prime_fd_to_handle() and
+drm_gem_prime_handle_to_fd() require that importers call dma_buf_attach()
+even if they never do actual device DMA, but only CPU access through
+dma_buf_vmap(). This is a problem for USB devices, which do not support DMA
+operations.
+
+To fix the issue, automatic page mappings should be removed from the
+buffer-sharing code. Fixing this is a bit more involved, since the import/export
+cache is also tied to &drm_gem_object.import_attach. Meanwhile we paper over
+this problem for USB devices by fishing out the USB host controller device, as
+long as that supports DMA. Otherwise importing can still needlessly fail.
+
+Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter
+
+Level: Advanced
+
+
 Better Testing
 ==============