Hello Martin, On 15.05.2024 21:26:17, Martin Kaiser wrote: > Thus wrote Martin Kaiser (martin@xxxxxxxxx): > > > > However this breaks SPI transfers, when I try to read out an MRAM I get: > > > > root@ecu02:~ hexdump -C /dev/mtd4 > > > [ 71.813807] spi_imx 43fa4000.spi: I/O Error in DMA TX > > > [ 71.819173] spi-nor spi0.2: SPI transfer failed: -110 > > > [ 71.829129] spi_master spi0: failed to transfer one message from queue > > > [ 71.843962] spi_master spi0: noqueue transfer failed > > > > So it would indeed be interesting if you ever managed to use DMA on > > > i.MX25. > > > I believe so. Looking into my notes from 2016 (when I last tried this), I got > > the -110 error when the SMC bit in CONREG wasn't set. But this should now be > > done in mx31_prepare_transfer if DMA is used... > > > I'll try to set up a test some time next week. > > I can now reproduce the dma tx error. My test board uses a dummy spidev device > on cspi1 and configures loopback on the cspi1 controller (disabling loopback > makes no difference). > > I'm relatively sure that this setup did work back in 2016/17. > > Commit 24bb244e02a6 ("ARM: i.MX25: globally disable supervisor protect") was > required before any DMA transfers started working on imx25. As far as I can > see, this code is still present. > > I'll look into this a bit more as time permits. have you found the time to look into this? regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung Nürnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
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