Android 7 Full 4k apps

dbe_dev

Been busy to get the rk3399 to output full 4k.

Found so far that one can set the  persist.sys.framebuffer.main to 3840x2160, this causes android to draw everything in 4k but it does not create a full 4k experience on the output because a bit of code in "hardware/rockchip/hwcomposer/hwcomposer.cpp" which is causing to report a 1080p screen in case the framebuffer is set to 2160p.

Worked around this by doing the following change in the SDK:

1. diff --git a/hardware/rockchip/hwcomposer/hwcomposer.cpp b/hardware/rockchip/hwcomposer/hwcomposer.cpp
   
2. index 173271f..2721dac 100755
   
3. --- a/hardware/rockchip/hwcomposer/hwcomposer.cpp
   
4. +++ b/hardware/rockchip/hwcomposer/hwcomposer.cpp
   
5. @@ -287,7 +287,7 @@ class DrmHotplugHandler : public DrmEventHandler {
   
6.      update_display_bestmode(hd, HWC_DISPLAY_EXTERNAL, extend);
   
7.      DrmMode mode = extend->best_mode();
   
8. 
   
9. -    if (mode.h_display() > mode.v_display() && mode.v_display() >= 2160) {
   
10. +    if (mode.h_display() > mode.v_display() && mode.v_display() > 2160) {
    
11.        hd->framebuffer_width = mode.h_display() * (1080.0 / mode.v_display());
    
12.        hd->framebuffer_height = 1080;
    
13.      } else {
    
14. @@ -1661,7 +1661,7 @@ static int hwc_get_display_configs(struct hwc_composer_device_1 *dev,
    
15.      /*
    
16.       * Limit to 1080p if large than 2160p
    
17.       */
    
18. -    if (hd->framebuffer_height >= 2160 && hd->framebuffer_width >= hd->framebuffer_height) {
    
19. +    if (hd->framebuffer_height > 2160 && hd->framebuffer_width >= hd->framebuffer_height) {
    
20.        hd->framebuffer_width = hd->framebuffer_width * (1080.0 / hd->framebuffer_height);
    
21.        hd->framebuffer_height = 1080;
    
22.      }

Copy the code

Also found some statements on needing to disable VOP_Little. Is this needed for android 7 and how do I do this for the android 7 SDK ?