imx-drm: ipuv3-plane: enable double buffering
This allows to update the buffer base address while the DMA
channel is running. It is needed to flip the frame buffer of
an active plane.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/imx-drm/ipuv3-plane.c b/drivers/staging/imx-drm/ipuv3-plane.c
index 85f49e6..16134d9 100644
--- a/drivers/staging/imx-drm/ipuv3-plane.c
+++ b/drivers/staging/imx-drm/ipuv3-plane.c
@@ -64,6 +64,7 @@
{
struct drm_gem_cma_object *cma_obj;
unsigned long eba;
+ int active;
cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
if (!cma_obj) {
@@ -76,8 +77,15 @@
eba = cma_obj->paddr + fb->offsets[0] +
fb->pitches[0] * y + (fb->bits_per_pixel >> 3) * x;
- ipu_cpmem_set_buffer(ipu_plane->ipu_ch, 0, eba);
- ipu_cpmem_set_buffer(ipu_plane->ipu_ch, 1, eba);
+
+ if (ipu_plane->enabled) {
+ active = ipu_idmac_get_current_buffer(ipu_plane->ipu_ch);
+ ipu_cpmem_set_buffer(ipu_plane->ipu_ch, !active, eba);
+ ipu_idmac_select_buffer(ipu_plane->ipu_ch, !active);
+ } else {
+ ipu_cpmem_set_buffer(ipu_plane->ipu_ch, 0, eba);
+ ipu_cpmem_set_buffer(ipu_plane->ipu_ch, 1, eba);
+ }
/* cache offsets for subsequent pageflips */
ipu_plane->x = x;
@@ -187,6 +195,7 @@
return ret;
}
ipu_cpmem_set_high_priority(ipu_plane->ipu_ch);
+ ipu_idmac_set_double_buffer(ipu_plane->ipu_ch, 1);
ipu_cpmem_set_stride(ipu_plane->ipu_ch, fb->pitches[0]);
ret = ipu_plane_set_base(ipu_plane, fb, src_x, src_y);