Fixed display corruption in smoothUpdate on M5Paper S3

[mikaryyn]

Using smoothUpdate on M5Paper S3 causes display corruption. It is easy to see in the photos I have attached; first is before the fix and second is after. The changes are very small, but I cannot say if this will work also on other panels.

Line 1759 is simple, there is an error in the comparison. Other two changes are a bit more difficult for me to explain. It changes ordering between DMA transfers and row-advance (ROW_STEP). Apparently the old ordering could interfere with the previous DMA transfer which is still ongoing and corrupt the display. First change is for the 1bpp path and second is for the 4bpp.

[mikaryyn]

I used this simple test program:

extern "C" void app_main(void)
{
    epd.initPanel(BB_PANEL_M5PAPERS3);
    epd.setMode(BB_MODE_4BPP);
    epd.clearWhite();
    epd.fillScreen(epd.getMode() == BB_MODE_4BPP ? 0xF : (epd.getMode() == BB_MODE_2BPP ? 3 : BBEP_WHITE));
    epd.drawLine(0, 0, epd.width() - 1, epd.height() - 1, BBEP_BLACK);
    epd.drawLine(epd.width() - 1, 0, 0, epd.height() - 1, BBEP_BLACK);
    epd.smoothUpdate(true, BBEP_WHITE);
    while (true) { vTaskDelay(pdMS_TO_TICKS(1000)); }
}