On Mon, Jan 15, 2024 at 12:20:50PM +0100, Ulf Hansson wrote: > Not sure exactly what problem you are trying to solve here, but I am > certainly happy to help, if I can. > > Can you perhaps point me to a couple of drivers that need to be converted? Sure. mmc_alloc_disk sets BLK_BOUNCE_HIGH for any mmc host that doesn't have a DMA mask set, which is a bit odd as all proper devices should have a valid DMA mask. I suspect platform devices might sometimes not have one, which historically was the wild west. A better indicator might be the use of page_address in the I/O path, which usually comes in the form of using the sg_virt() helper. For drivers/mmc/ that seems to be: davinci_mmc, moxart-mmc, mvsdio, mxcmmc, omap, sdhci-esdhc-mcf and sh_mmcif. tmio_mmc_core on the other hand seems to have code properly kmapping a scatterlist, which might be worth lifting into a common helper to help the above drivers. > > Kind regards > Uffe ---end quoted text---