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| author |   Thierry Reding <treding@nvidia.com> | 2021-03-26 15:51:36 +0100 |
|---|---|---|
| committer | Thierry Reding <treding@nvidia.com> | 2021-03-31 17:42:14 +0200 |
| commit | 476e93205ff61a6507bcba28f4f01269b65ebb38 (patch) | |
| tree | a3b4cae2dd3678b586e7fde0e051ae92893a30c1 /drivers/gpu/drm/tegra/plane.c | |
| parent | drm/tegra: fb: Add diagnostics for framebuffer modifiers (diff) | |
| download | linux-dev-476e93205ff61a6507bcba28f4f01269b65ebb38.tar.xz linux-dev-476e93205ff61a6507bcba28f4f01269b65ebb38.zip | |
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>
Diffstat (limited to 'drivers/gpu/drm/tegra/plane.c')
| -rw-r--r-- | drivers/gpu/drm/tegra/plane.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c index 19e8847a164b..793da5d675d2 100644 --- a/drivers/gpu/drm/tegra/plane.c +++ b/drivers/gpu/drm/tegra/plane.c @@ -119,6 +119,14 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state) dma_addr_t phys_addr, *phys; struct sg_table *sgt; + /* + * If we're not attached to a domain, we already stored the + * physical address when the buffer was allocated. If we're + * part of a group that's shared between all display + * controllers, we've also already mapped the framebuffer + * through the SMMU. In both cases we can short-circuit the + * code below and retrieve the stored IOV address. + */ if (!domain || dc->client.group) phys = &phys_addr; else |