drm/i915: Pass DMA_ATTR_NO_WARN to dma_map_sg()
authorChris Wilson <chris@chris-wilson.co.uk>
Thu, 4 Jan 2018 16:38:42 +0000 (16:38 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Thu, 4 Jan 2018 18:48:53 +0000 (18:48 +0000)
commit82e07602d22ab45cd90e31b62a87f0fa37ca428f
treed8689efeb51272ef206f1d53b95476336c435c33
parentc68ce69910e3b292afc138e12725399d3b0fb347
drm/i915: Pass DMA_ATTR_NO_WARN to dma_map_sg()

In some iommu, e.g. swiotlb, the available space can be quite limited.
So we employ a trial-and-error approach to seeing if our large
contiguous chunks can fit, and if that fails we try again with smaller
chunks after trying to free our own lazily allocated blobs. As we use a
trial-and-error approach, we do not want dma_map_sg() to emit a WARN of
its own accord, we want to gracefully report the error back to the caller
instead.

Note that our noisy culprit, swiotlb, doesn't honour the flag, yet.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180104163842.11635-1-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_gem_gtt.c