Searched hist:"273 da5a046965ccf0ec79eb63f2d5173467e20fa" (Results 1 – 3 of 3) sorted by relevance
/linux/drivers/gpu/drm/tegra/ |
H A D | plane.c | diff 273da5a046965ccf0ec79eb63f2d5173467e20fa Tue Feb 04 14:59:25 CET 2020 Thierry Reding <treding@nvidia.com> drm/tegra: Reuse IOVA mapping where possible
This partially reverts the DMA API support that was recently merged because it was causing performance regressions on older Tegra devices. Unfortunately, the cache maintenance performed by dma_map_sg() and dma_unmap_sg() causes performance to drop by a factor of 10.
The right solution for this would be to cache mappings for buffers per consumer device, but that's a bit involved. Instead, we simply revert to the old behaviour of sharing IOVA mappings when we know that devices can do so (i.e. they share the same IOMMU domain).
Cc: <stable@vger.kernel.org> # v5.5 Reported-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
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H A D | gem.c | diff 273da5a046965ccf0ec79eb63f2d5173467e20fa Tue Feb 04 14:59:25 CET 2020 Thierry Reding <treding@nvidia.com> drm/tegra: Reuse IOVA mapping where possible
This partially reverts the DMA API support that was recently merged because it was causing performance regressions on older Tegra devices. Unfortunately, the cache maintenance performed by dma_map_sg() and dma_unmap_sg() causes performance to drop by a factor of 10.
The right solution for this would be to cache mappings for buffers per consumer device, but that's a bit involved. Instead, we simply revert to the old behaviour of sharing IOVA mappings when we know that devices can do so (i.e. they share the same IOMMU domain).
Cc: <stable@vger.kernel.org> # v5.5 Reported-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
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/linux/drivers/gpu/host1x/ |
H A D | job.c | diff 273da5a046965ccf0ec79eb63f2d5173467e20fa Tue Feb 04 14:59:25 CET 2020 Thierry Reding <treding@nvidia.com> drm/tegra: Reuse IOVA mapping where possible
This partially reverts the DMA API support that was recently merged because it was causing performance regressions on older Tegra devices. Unfortunately, the cache maintenance performed by dma_map_sg() and dma_unmap_sg() causes performance to drop by a factor of 10.
The right solution for this would be to cache mappings for buffers per consumer device, but that's a bit involved. Instead, we simply revert to the old behaviour of sharing IOVA mappings when we know that devices can do so (i.e. they share the same IOMMU domain).
Cc: <stable@vger.kernel.org> # v5.5 Reported-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
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