[PATCH] drm/sun4i: layers: Use drm_fb_dma_get_gem_addr() to get display memory

Chen-Yu Tsai
2026-03-09T16:56:46Z

Commit 4636ce93d5b2 ("drm/fb-cma-helper: Add drm_fb_cma_get_gem_addr()")
adds a new helper, which covers fetching a drm_framebuffer's GEM object
and calculating the buffer address for a given plane.

This patch uses this helper to replace our own open coded version of the
same function.

Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
---
drivers/gpu/drm/sun4i/sun8i_ui_layer.c | 16 ++-------------
drivers/gpu/drm/sun4i/sun8i_vi_layer.c | 27 ++------------------------
2 files changed, 4 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_ui_layer.c b/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
index f08f6da55dd0..72c92203ae63 100644
--- a/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
+++ b/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
@@ -124,25 +124,13 @@ static void sun8i_ui_layer_update_buffer(struct sun8i_layer *layer,
{
struct drm_plane_state *state = plane->state;
struct drm_framebuffer *fb = state->fb;
- struct drm_gem_dma_object *gem;
dma_addr_t dma_addr;
u32 ch_base;
- int bpp;

ch_base = sun8i_channel_base(layer);

- /* Get the physical address of the buffer in memory */
- gem = drm_fb_dma_get_gem_obj(fb, 0);
-
- DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->dma_addr);
-
- /* Compute the start of the displayed memory */
- bpp = fb->format->cpp[0];
- dma_addr = gem->dma_addr + fb->offsets[0];
-
- /* Fixup framebuffer address for src coordinates */
- dma_addr += (state->src.x1 >> 16) * bpp;
- dma_addr += (state->src.y1 >> 16) * fb->pitches[0];
+ /* Get the start of the displayed memory */
+ dma_addr = drm_fb_dma_get_gem_addr(fb, state, 0);

/* Set the line width */
DRM_DEBUG_DRIVER("Layer line width: %d bytes\n", fb->pitches[0]);
diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
index ca3ab59e108d..cd8d6c2da0c7 100644
--- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
+++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
@@ -197,38 +197,15 @@ static void sun8i_vi_layer_update_buffer(struct sun8i_layer *layer,
struct drm_plane_state *state = plane->state;
struct drm_framebuffer *fb = state->fb;
const struct drm_format_info *format = fb->format;
- struct drm_gem_dma_object *gem;
- u32 dx, dy, src_x, src_y;
dma_addr_t dma_addr;
u32 ch_base;
int i;

ch_base = sun8i_channel_base(layer);

- /* Adjust x and y to be dividable by subsampling factor */
- src_x = (state->src.x1 >> 16) & ~(format->hsub - 1);
- src_y = (state->src.y1 >> 16) & ~(format->vsub - 1);
-
for (i = 0; i < format->num_planes; i++) {
- /* Get the physical address of the buffer in memory */
- gem = drm_fb_dma_get_gem_obj(fb, i);
-
- DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->dma_addr);
-
- /* Compute the start of the displayed memory */
- dma_addr = gem->dma_addr + fb->offsets[i];
-
- dx = src_x;
- dy = src_y;
-
- if (i > 0) {
- dx /= format->hsub;
- dy /= format->vsub;
- }
-
- /* Fixup framebuffer address for src coordinates */
- dma_addr += dx * format->cpp[i];
- dma_addr += dy * fb->pitches[i];
+ /* Get the start of the displayed memory */
+ dma_addr = drm_fb_dma_get_gem_addr(fb, state, i);

/* Set the line width */
DRM_DEBUG_DRIVER("Layer %d. line width: %d bytes\n",
--
2.47.3