On Sat, Apr 03, 2021 at 06:58:24PM +0200, Maciej W. Rozycki wrote: > Last but not least I do hope you do not plan to retire ISA DMA bounce > buffering support for drivers/block/floppy.c, as there is hardly an > alternative available (I do have a single SCSI<->FDD interface built > around an Intel 8080 CPU, in the half-height 5.25" drive form factor, but > such devices are exceedingly rare, and then you need a suitable parallel > SCSI host too). The floppy driver already uses its own bounce buffering for addressing limitations, and only the kernel bounce buffering to avoid getting fed highmem patches. Please take a look at this series to clean up the latter: https://lore.kernel.org/linux-block/20210406061755.811522-1-hch@xxxxxx/T/#u > Would it be feasible to convert it and any other drivers for ISA DMA > devices (like those support for which you propose to remove here) still > have users who could verify operation to the IOMMU framework? I've converted the only once that still has signs of having users in the last 10 or so years.