As it isn't supported by hardware. At least, RK3399 doesn't support it. From the datasheet[1] ("1.2.10 Video IN/OUT", "Display Interface", p. 17):
Support AFBC function co-operation with GPU * support 2560x1600 UI Manually tested on RockPro64 (rk3399): - ARM_AFBC modifier is used for 1920x1080 - DRM_FORMAT_MOD_LINEAR modifier us used for 3840x2160 - No noise on the screen when sway is running in 4k - Dynamic resolution switching works correctly in sway Signed-off-by: Konstantin Shabanov <m...@etehtsea.me> Cc: Daniel Stone <dan...@fooishbar.org> Cc: Andy Yan <andys...@163.com> Reported-by: Dan Callaghan <d...@djc.id.au> Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7968 [1]: https://opensource.rock-chips.com/images/d/d7/Rockchip_RK3399_Datasheet_V2.1-20200323.pdf --- V2 -> V3: Run check only on rk3399 V1 -> V2: Move the check to the fb_create callback Hi Andy and Daniel! Thank you for the review! Best wishes, Konstantin drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c index dcc1f07632c3..6ca757f80a30 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c @@ -5,6 +5,7 @@ */ #include <linux/kernel.h> +#include <linux/of.h> #include <drm/drm.h> #include <drm/drm_atomic.h> @@ -17,6 +18,9 @@ #include "rockchip_drm_drv.h" #include "rockchip_drm_fb.h" #include "rockchip_drm_gem.h" +#include "rockchip_drm_vop.h" + +#define RK3399_AFBC_MAX_WIDTH 2560 static const struct drm_framebuffer_funcs rockchip_drm_fb_funcs = { .destroy = drm_gem_fb_destroy, @@ -52,6 +56,15 @@ rockchip_fb_create(struct drm_device *dev, struct drm_file *file, } if (drm_is_afbc(mode_cmd->modifier[0])) { + if (of_machine_is_compatible("rockchip,rk3399")) { + if (mode_cmd->width > RK3399_AFBC_MAX_WIDTH) { + DRM_DEBUG_KMS("AFBC is not supported for the width %d (max %d)\n", + mode_cmd->width, + RK3399_AFBC_MAX_WIDTH); + return ERR_PTR(-EINVAL); + }; + } + int ret, i; ret = drm_gem_fb_afbc_init(dev, mode_cmd, afbc_fb); base-commit: 4890d68db651562ea80250f2c93205a5c0327a6a -- 2.48.1