Hi Stefan, On Wednesday 15 April 2015, 21:00:26 wrote Stefan Wahren: > Am 15.04.2015 um 11:56 schrieb Noralf Trønnes: > > Add slave transfer capability to BCM2835 dmaengine driver. > > This patch is pulled from the bcm2708-dmaengine driver in the > > Raspberry Pi repo. The work was done by Gellert Weisz. > > > > Tested with the bcm2835-mmc driver from the same repo. > > why not with the upstream kernel? I also looked at slave dma support, especially for use in mmc. It turns our that bcm2835-mmc is written more or less completly new. Mainline linux uses sdhci "framework" which internally uses the SDMA and/or ADMA (both internal, to SD/MMC controller, DMA units) which can be supported by an SDHCI compatible controller. AFAIK the SD/MMC controller in bcm2835 lacks both that is why the driver only uses PIO. I dunno if external DMA usage can so easily be integrated into the sdhci, I have my doubts. Best regards, Alexander -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
