Hi, The following patch set is a result of looking at the ADMA errors observed on SolidRun's LX2160A board, caused by coherency mismatch between DT and hardware. The first patch improves the debugging by dumping the ADMA table using the DMA address, which can be compared with the DMA address reported in the register dump. It also prints the interrupt status that we read, whereas the register dump contains the _cleared_ interrupt status. The second patch modifies sdhci-of-esdhc to set the DMA snoop bit depending on whether DT marks the device as coherent or not. With this patch applied, driver will now set the hardware to match the contents of DT, rather than always DMA snooping. As explained by Robin, if the hardware snoops the CPU caches, but the DMA API layer does not expect this, the hardware can read stale data. The hardware state and the DMA API must always agree wrt this, for the sake of data integrity. Mismatch risks substantial filesystem corruption. The third patch marks the LX2160A esdhc devices as dma-coherent. Other users of the driver are not touched; I do not have the information to know whether DMA snooping (coherency) is available on other SoCs using this driver. However, given the risk of filesystem corruption, it is important no matter what that the DMA API layer and the hardware agree - even if it means defaulting to being non-coherent. arch/arm64/boot/dts/freescale/fsl-lx2160a.dtsi | 2 ++ drivers/mmc/host/sdhci-of-esdhc.c | 7 ++++++- drivers/mmc/host/sdhci.c | 15 ++++++++++----- 3 files changed, 18 insertions(+), 6 deletions(-) -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
