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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-18 17:17:06 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-18 22:36:56 +0100 |
| commit | 2efb813d5388e18255c54afac77bd91acd586908 (patch) | |
| tree | 170d5d22c05d5ed2614d4afdcb606e0f6e42dad0 /drivers/gpu/drm/i915/intel_fbc.c | |
| parent | 821188778b9be2050d45490c4b2b009d51f041e0 (diff) | |
| download | talos-op-linux-2efb813d5388e18255c54afac77bd91acd586908.tar.gz talos-op-linux-2efb813d5388e18255c54afac77bd91acd586908.zip | |
drm/i915: Fallback to using unmappable memory for scanout
The existing ABI says that scanouts are pinned into the mappable region
so that legacy clients (e.g. old Xorg or plymouthd) can write directly
into the scanout through a GTT mapping. However if the surface does not
fit into the mappable region, we are better off just trying to fit it
anywhere and hoping for the best. (Any userspace that is capable of
using ginormous scanouts is also likely not to rely on pure GTT
updates.) With the partial vma fault support, we are no longer
restricted to only using scanouts that we can pin (though it is still
preferred for performance reasons and for powersaving features like
FBC).
v2: Skip fence pinning when not mappable.
v3: Add a comment to explain the possible ramifications of not being
able to use fences for unmappable scanouts.
v4: Rebase to skip over some local patches
v5: Rebase to defer until after we have unmappable GTT fault support
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Deepak S <deepak.s@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-27-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/intel_fbc.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_fbc.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 40bf2e4c804d..37415f96f906 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -776,6 +776,10 @@ static bool intel_fbc_can_activate(struct intel_crtc *crtc) /* The use of a CPU fence is mandatory in order to detect writes * by the CPU to the scanout and trigger updates to the FBC. + * + * Note that is possible for a tiled surface to be unmappable (and + * so have no fence associated with it) due to aperture constaints + * at the time of pinning. */ if (cache->fb.tiling_mode != I915_TILING_X || cache->fb.fence_reg == I915_FENCE_REG_NONE) { |
