DRAW_WITH_DMA only draw half of the screen

[guedesite]

Hi, I am working on an ESP32-WROOM-32UE with arduino-esp32 and an LCD_ST7789_240 (40MHz) screen.

This bug occurs with the spilcdWriteDataBlock function and the DRAW_WITH_DMA flag, tested with the JPEGDEC example esp32_jpeg.

My image, adapted to the resolution of my screen, has the following description:

// Data size = 4213 bytes
//
// JFIF, Compression=JPEG, Size: 240 x 240, 24-Bpp
//

Changing the resolution, the quality of my JPEG, or the SPI frequency didn't make a difference.

I don't have the capability to manually test if the problem is related to JPEG decoding or not. However, I did test the PNGdec png_transparency example, and spilcdWritePixelsMasked functions correctly with DRAW_WITH_DMA. So, I assume that the problem does not come from my ESP32.

[bitbank2]

Can you share the complete sketch that you're running, along with the exact image? From the description and photo, I don't have enough info to debug the problem.

[guedesite]

@bitbank2 here is it test_jpeg.zip

[bitbank2]

I was able to reproduce the problem and am working on a fix. It has to do with the max transaction size of a DMA write (4092 bytes).

[bitbank2]

ok, I pushed new code to fix it. Be advised that I changed the spilcdInit function to add a new parameter - bUseDMA. I needed this for the SD card to work on the M5Stack Core2. I recommend using the C++ api instead of the old C API.