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i.MX6QP + Qt5 Cinematic graphics issue

Question asked by Gary Bisson on Mar 21, 2016
Latest reply on Apr 4, 2016 by Danielle Loader
Branched to a new discussion



Running the Qt5 Cinematic Experience shows some graphics issues on 6QP only.


Here are some details on the setup to reproduce the issue:

- Qt5.5 or Qt5.6 (tested with both)

- Yocto Jethro or Buildroot master (as of today, for latest graphics libraries support)

- Using a platform that supports both 6Q and 6QP, in my case the Nitrogen6_MAX and Nitrogen6QP_MAX, the cpu is the only difference

- Kernel 3.14.53, in my case:

GitHub - boundarydevices/linux-imx6 at boundary-imx_3.14.52_1.1.0_ga: Boundary Devices Kernel tree for i.MX6

   -> this issue was also present with 3.14.38-6qp-beta + p6.x libraries, but at the time it was beta so not worth mentioning

- imx-gpu-viv + kernel-module-imx-gpu-viv version 5.0.11 p7.4

- Qt5 Cinematic Experience:

meta-qt5/ at master · meta-qt5/meta-qt5 · GitHub


Please find attached two screenshots, one shows the output when running on a 6Q, the other is running on the 6QP, using the exact same SDCard, exact same kernel, only the device tree differs (includes imx6q.dtsi in one case, imx6qp.dtsi in the other).


Please dismiss the tearing that can be seen in those screenshots, this is due to the software used to grab the framebuffer (fbgrab) which doesn't wait for vsync. Instead, focus on the rectangles around the different stars that appears on the background. It sounds like some alpha blending isn't managed properly on the 6QP.


Let me know if you have any question regarding the issue, which hopefully will be fixed in next Vivante release.