Hello Simon,
I had noticed your DMA fix PR (https://github.com/apache/incubator-nuttx/ pull/5513) so I tested it with HSMCI SD card interface. There are still some problems when I undef HSCMI_NOTXDMA at https://github.com/apache/incubator- nuttx/blob/master/arch/arm/src/samv7/sam_hsmci.c#L122. The card unmounts itself as soon as I try to write to it with 'echo' command. I think this might be quite a different problem that can be sam_hsmci.c related as some other TX DMAs are working. I tested DMA with SPI and it works (althought I can write only to one half of the display but that might be some my problems in configuration if all your tests were fine) as well as DMA with USB device. I will take a look into HSCMI with DMA in the future, currently more critical problem for our implementation at Elektroline.cz company is DMA support for U(S)ART. That will also be a nice way to find if there are some further DMA TX bugs. Best regards, Michal Lenc ---------- Původní e-mail ---------- Od: Simon Filgis <si...@ingenieurbuero-filgis.de> Komu: dev@nuttx.apache.org Datum: 14. 2. 2022 16:33:32 Předmět: Re: SPI with DMA on SAME70 "Dear all, I started to follow up this topic. Found that one in sam_hsmci.c: /* There is some unresolved issue with the SAMV7 DMA. TX DMA is currently * disabled. */ #undef HSCMI_NORXDMA /* Define to disable RX DMA */ *#define HSCMI_NOTXDMA 1 /* Define to disable TX DMA */* That fits my (and Michael Lenc's) experience that DMA peripheral to memory works. Memory to the peripheral seems broken though. I will therefore debug *sam_xdmax.c*. Even if I find some odd comments on DMA timeouts in sam_spi.c. If anybody has a better idea, or remembers details ;), please give feedback. BR, Simon -- Hard- and Softwaredevelopment Consultant Ingenieurbüro-Filgis USt-IdNr.: DE305343278 On Tue, Feb 8, 2022 at 11:52 AM Simon Filgis <si...@ingenieurbuero-filgis.de > wrote: > 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 > "
