Hello Michael, Thank you for your answer. That is true, SPI driver's initial flag setup is 0.
The flags are evaluated dynamically and very meaningful within spi_exchange() and set via sam_dmaconfig(spics->rxdma, rxflags); sam_dmaconfig(spics->txdma, txflags); I will try with setup initial flags to try. Any hint to debug is appreciated :) Simon -- Hard- and Softwaredevelopment Consultant Ingenieurbüro-Filgis USt-IdNr.: DE305343278 On Tue, Feb 8, 2022 at 12:17 PM Michal Lenc <michall...@seznam.cz> wrote: > Hello Simon, > > > > I did take a look into SPI driver for SAME70 a few months ago. The one > thing > that was a little bit weird to me was the lack of DMA flags passed to sam_ > dmachannel() function (somewhere here https://github.com/apache/incubator- > nuttx/blob/master/arch/arm/src/samv7/sam_spi.c#L2043 > <https://github.com/apache/incubator-nuttx/blob/master/arch/arm/src/samv7/sam_spi.c#L2043>) > compared to the flags > I needed to select for ADC DMA support to function correctly (https:// > > github.com/apache/incubator-nuttx/blob/master/arch/arm/src/samv7/sam_afec.c# > L1125 > <http://github.com/apache/incubator-nuttx/blob/master/arch/arm/src/samv7/sam_afec.c#L1125>). > I didn't invest more time into it as we had other priorities back > then and I think we sticked with SPI without DMA. But it could be one of > the > problems. > > > > > You can also take a look into sam_afec.c file, the DMA is working fine > there. Hope this helps. > > Best regards, > Michal Lenc > > ---------- Původní e-mail ---------- > Od: Simon Filgis <si...@ingenieurbuero-filgis.de> > Komu: dev@nuttx.apache.org > Datum: 8. 2. 2022 11:52:38 > Předmět: SPI with DMA on SAME70 > "Dear all, > > I'm using ST7789.c in combination with lvgl-lib. > > The bottleneck to the display is the SPI communication. But even if I > increase the SPI frequency to 24MHz, it does not get faster. This is > because of constant delay between the bytes. > > I guessed that this can be improved using DMA. But that does not seem to > work out of the box. In the SPI TX callback the result of the DMA transfer > is -4. The transfer is not executed. > > Can anybody give me a hint on what to do? > > Best regards, > > Simon > > -- > Hard- and Softwaredevelopment Consultant > Ingenieurbüro-Filgis > USt-IdNr.: DE305343278 > "
