mirror of https://gitee.com/openkylin/linux.git
drm/tegra: gem: Add a clarifying comment
Clarify when a fixed IOV address can be used and when a buffer has to be mapped before the IOVA can be used. Signed-off-by: Thierry Reding <treding@nvidia.com>
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@ -119,6 +119,14 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
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dma_addr_t phys_addr, *phys;
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dma_addr_t phys_addr, *phys;
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struct sg_table *sgt;
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struct sg_table *sgt;
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/*
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* If we're not attached to a domain, we already stored the
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* physical address when the buffer was allocated. If we're
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* part of a group that's shared between all display
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* controllers, we've also already mapped the framebuffer
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* through the SMMU. In both cases we can short-circuit the
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* code below and retrieve the stored IOV address.
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*/
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if (!domain || dc->client.group)
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if (!domain || dc->client.group)
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phys = &phys_addr;
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phys = &phys_addr;
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else
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else
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