diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index ee59da4a0172..4e5922c89d7b 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -361,13 +361,6 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend, paddr = drm_fb_cma_get_gem_addr(fb, state, 0); DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr); - /* - * backend DMA accesses DRAM directly, bypassing the system - * bus. As such, the address range is different and the buffer - * address needs to be corrected. - */ - paddr -= PHYS_OFFSET; - if (fb->format->is_yuv) return sun4i_backend_update_yuv_buffer(backend, fb, paddr); @@ -803,6 +796,27 @@ static int sun4i_backend_bind(struct device *dev, struct device *master, dev_set_drvdata(dev, backend); spin_lock_init(&backend->frontend_lock); + if (of_find_property(dev->of_node, "interconnects", NULL)) { + /* + * This assume we have the same DMA constraints for all our the + * devices in our pipeline (all the backends, but also the + * frontends). This sounds bad, but it has always been the case + * for us, and DRM doesn't do per-device allocation either, so + * we would need to fix DRM first... + */ + ret = of_dma_configure(drm->dev, dev->of_node, true); + if (ret) + return ret; + } else { + /* + * If we don't have the interconnect property, most likely + * because of an old DT, we need to set the DMA offset by hand + * on our device since the RAM mapping is at 0 for the DMA bus, + * unlike the CPU. + */ + drm->dev->dma_pfn_offset = PHYS_PFN_OFFSET; + } + backend->engine.node = dev->of_node; backend->engine.ops = &sun4i_backend_engine_ops; backend->engine.id = sun4i_backend_of_get_id(dev->of_node);