How to user two display framebuffer?

How-to
1

Description

i use stm32f746 , I imitate the f7 example (use dma2d & dma) to driver my display(1024*600),when i use benckmark,I click the wallpaper button, i can find the display refreshing that from top to bot slowly brush.

What MCU/Processor/Board and compiler are you using?

STM32F746

What do you want to achieve?

I want use two framebuffer, When the all data are ready, I switch ltdc base framebuffer addr to switch the diplay context directly, without slowly brush effect.

What have you tried so far?

Code to reproduce

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Screenshot and/or video

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2

Take a look at this: https://docs.littlevgl.com/en/html/porting/display.html#display-buffer

3

I test two full size buffer,but I still see the brush effect.
Can i change directly the ltdc base addr ? Lvgl provide this API?

And i find ,If data is all in Ram(not in flash),Use two 10 line buffer in internal Ram which is faster than two full buffer in external SDram when switch total screen Data.

4

Is the D-Cache enabled? Without it, I think SDRAM will be very slow compared to SRAM.