diff options
| author | Dmitry Osipenko <digetx@gmail.com> | 2019-03-07 01:55:19 +0300 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2019-04-18 11:48:09 +0200 |
| commit | 61b51fb51c01a519a249d28ec55c6513a13be5a3 (patch) | |
| tree | 5707e7222b4a94dc6dfdc7b13244c2ef3ae9daab /drivers/gpu/drm/tegra/gem.c | |
| parent | 11c632e1cfd3dcb49f2d04625d31c818a4c3b426 (diff) | |
| download | linux-61b51fb51c01a519a249d28ec55c6513a13be5a3.tar.bz2 | |
drm/tegra: gem: Fix CPU-cache maintenance for BO's allocated using get_pages()
The allocated pages need to be invalidated in CPU caches. On ARM32 the
DMA_BIDIRECTIONAL flag only ensures that data is written-back to DRAM and
the data stays in CPU cache lines. While the DMA_FROM_DEVICE flag ensures
that the corresponding CPU cache lines are getting invalidated and nothing
more, that's exactly what is needed for a newly allocated pages.
This fixes randomly failing rendercheck tests on Tegra30 using the
Opentegra driver for tests that use small-sized pixmaps (10x10 and less,
i.e. 1-2 memory pages) because apparently CPU reads out stale data from
caches and/or that data is getting evicted to DRAM at the time of HW job
execution.
Fixes: bd43c9f0fa1f ("drm/tegra: gem: Map pages via the DMA API")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/tegra/gem.c')
| -rw-r--r-- | drivers/gpu/drm/tegra/gem.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index 4f80100ff5f3..4cce11fd8836 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -204,7 +204,7 @@ static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo) { if (bo->pages) { dma_unmap_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents, - DMA_BIDIRECTIONAL); + DMA_FROM_DEVICE); drm_gem_put_pages(&bo->gem, bo->pages, true, true); sg_free_table(bo->sgt); kfree(bo->sgt); @@ -230,7 +230,7 @@ static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo) } err = dma_map_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents, - DMA_BIDIRECTIONAL); + DMA_FROM_DEVICE); if (err == 0) { err = -EFAULT; goto free_sgt; |