[PATCH 0/4] drm/nouveau: Miscellaneous fixes

Thierry Reding thierry.reding at gmail.com
Mon Sep 16 14:19:22 UTC 2019

From: Thierry Reding <treding at nvidia.com>

Hi Ben,

these are fixes for a couple of issues that I've been running into when
testing on various Tegra boards. The first two patches fix up issues in
the fix that I had sent out earlier to fix the regression introduced in
drm-misc-next. The first one is critical because it avoids a BUG_ON as
reported by Ilia, while the second is less critical, but restores the
locking correctness (at least to the best of my knowledge).

Patch 3 is something that I think was also caused by the reservation
object rework and is kind of a continuation of my earlier attempt to fix
the VMA node sharing breakage. The current ordering between TTM and GEM
teardown is causing a DEBUG_LOCKS_WARN_ON() because GEM cleanup already
freed a mutex that TTM teardown will still want to use.

Lastly, patch 4 is quite uncritical, but it's a one-line change that is
causing an ugly (but harmless) external memory address decode error on
Tegra210 and later. It seems that for some reason clearing this register
will cause a DMA operation to be started by the GPU. I've verified that
it's tied to exactly that register write by modifying the value written
to the register, and stalling for a couple of seconds after the register
write. The address decode error reflects the value written into this
register exactly and it always happens a couple of milliseconds after
this write.


Thierry Reding (4):
  drm/nouveau: Fix fallout from reservation object rework
  drm/nouveau: prime: Extend DMA reservation object lock
  drm/nouveau: Fix ordering between TTM and GEM release
  drm/nouveau: gm20b: Avoid BAR1 teardown during init

 drivers/gpu/drm/nouveau/nouveau_bo.c          | 26 +++++++++++-------
 drivers/gpu/drm/nouveau/nouveau_bo.h          |  4 +--
 drivers/gpu/drm/nouveau/nouveau_gem.c         |  7 ++---
 drivers/gpu/drm/nouveau/nouveau_prime.c       | 27 ++++++++++++-------
 .../gpu/drm/nouveau/nvkm/subdev/bar/gm20b.c   |  1 -
 5 files changed, 39 insertions(+), 26 deletions(-)


More information about the dri-devel mailing list