From: Thierry Reding <treding@xxxxxxxxxx> 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@xxxxxxxxxx> --- drivers/gpu/drm/tegra/plane.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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 -- 2.30.2
