Hi Michael, Op zo 10 nov. 2019 om 03:36 schreef Michael Schmitz <schmitzmic@xxxxxxxxx>: > All of the old board-specific drivers used a max transfer length of > 0x1000000, only the fastlane driver used 0xfffc. Yes, I also found this when checking the old drivers. > That lower limit might > be due to a DMA limitation on the fastlane board. We could accommodate > the different limit for this board by using a board-specific > dma_length_limit() callback... Yes, I think that's the best idea for now. Oktagon also used to have a different limit but that was never ported to the new ESP core. > > case for any of the cards the zorro_esp drives, it might be better to > > lower the max length to 61440 (64k-4k) so the residual is a page. > > For the benefit of keeping the code simple, and avoid retesting the > fastlane board, that might indeed be the better solution. But it's slower... :-P Also, I may be adding another board-specific version for the Blizzard 12x0 IV to enable 24-bit transfers, like the am53c974 driver does, in a later patch. Kind regards, Kars.
