1. 10 Jun, 2021 1 commit
  2. 09 Jun, 2021 12 commits
  3. 08 Jun, 2021 6 commits
  4. 07 Jun, 2021 15 commits
  5. 06 Jun, 2021 4 commits
  6. 05 Jun, 2021 1 commit
  7. 04 Jun, 2021 1 commit
    • Alyssa Rosenzweig's avatar
      drm/panfrost: Add AFBC_FEATURES parameter · 3e2926f8
      Alyssa Rosenzweig authored
      The value of the AFBC_FEATURES register is required by userspace to
      determine AFBC support on Bifrost. A user on our IRC channel (#panfrost)
      reported a workload that raised a fault on one system's Mali G31 but
      worked flawlessly with another system's Mali G31. We determined the
      cause to be missing AFBC support on one vendor's Mali implementation --
      it turns out AFBC is optional on Bifrost!
      
      Whether AFBC is supported or not is exposed in the AFBC_FEATURES
      register on Bifrost, which reads back as 0 on Midgard. A zero value
      indicates AFBC is fully supported, provided the architecture itself
      supports AFBC, allowing backwards-compatibility with Midgard. Bits 0 and
      15 indicate that AFBC support is absent for texturing and rendering
      respectively.
      
      The user experiencing the fault reports that AFBC_FEATURES reads back
      0x10001 on their system, confirming the architectural lack of AFBC.
      Userspace needs this parameter to know to disable AFBC on that
      chip, and perhaps others.
      
      v2: Fix typo from copy-paste fail.
      
      v3: Bump the UABI version. This commit was cherry-picked from another
      series so chalking this up to a rebase fail.
      Signed-off-by: default avatarAlyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
      Reviewed-by: default avatarSteven Price <steven.price@arm.com>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
      Signed-off-by: default avatarSteven Price <steven.price@arm.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20210604130011.3203-1-alyssa.rosenzweig@collabora.com
      3e2926f8