Op 30-06-17 om 15:56 schreef Daniel Vetter:

On Wed, Jun 28, 2017 at 03:28:11PM +0200, Maarten Lankhorst wrote:

quoted

We want to change swap_state to wait indefinitely, but to do this
swap_state should wait interruptibly. This requires propagating
the error to each driver. All drivers have changes to deal with the
clean up. In order to allow easy reverting, the commit that changes
behavior is separate so someone only has to revert that for testing.

Nouveau has a small bugfix, if drm_atomic_helper_wait_for_fences
failed cleanup_planes was not called.

Cc: Boris Brezillon <redacted>
Cc: David Airlie <redacted>
Cc: Daniel Vetter <redacted>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <redacted>
Cc: CK Hu <redacted>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Rob Clark <redacted>
Cc: Ben Skeggs <redacted>
Cc: Thierry Reding <redacted>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Jyri Sarha <redacted>
Cc: Tomi Valkeinen <redacted>
Cc: Eric Anholt <redacted>
Cc: dri-devel at lists.freedesktop.org
Cc: linux-kernel at vger.kernel.org
Cc: intel-gfx at lists.freedesktop.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-mediatek at lists.infradead.org
Cc: linux-arm-msm at vger.kernel.org
Cc: freedreno at lists.freedesktop.org
Cc: nouveau at lists.freedesktop.org
Cc: linux-tegra at vger.kernel.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

We kinda need to backport this to older kernels, but I don't really see
how :( Maybe we should split this up:
patch 1: Change to int return type
patches 2-(n-1): Driver conversions
patch n: __must_check addition

That would at least somewhat make this backportable ...

quoted

---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 14 ++++++++++++--
 drivers/gpu/drm/drm_atomic_helper.c          | 18 ++++++++++++------
 drivers/gpu/drm/i915/intel_display.c         | 10 +++++++++-
 drivers/gpu/drm/mediatek/mtk_drm_drv.c       |  7 ++++++-
 drivers/gpu/drm/msm/msm_atomic.c             | 14 +++++++++-----
 drivers/gpu/drm/nouveau/nv50_display.c       | 10 ++++++++--
 drivers/gpu/drm/tegra/drm.c                  |  7 ++++++-
 drivers/gpu/drm/tilcdc/tilcdc_drv.c          |  6 +++++-
 drivers/gpu/drm/vc4/vc4_kms.c                | 21 +++++++++++++--------
 include/drm/drm_atomic_helper.h              |  4 ++--
 10 files changed, 82 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 516d9547d331..d4f787bf1d4a 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -544,9 +544,11 @@ static int atmel_hlcdc_dc_atomic_commit(struct drm_device *dev,
 		goto error;
 	}
 
-	/* Swap the state, this is the point of no return. */
-	drm_atomic_helper_swap_state(state, true);

Push the swap_state up over the commit setup (but after the allocation)
and there's no more a problem with unrolling.

This can't be done higher up because of the interruptible wait.

Unless we change the patch series to move the waiting for hw_done to a separate step and get rid of the stall argument to swap_state once everything is converted. This could be useful for all drivers that have some kind of setup, because we could move the wait up slightly to suit the drivers needs.

~Maarten