On Sun, Nov 10, 2024 at 4:59 PM Maciej W. Rozycki <macro@xxxxxxxxxxx> wrote: > It's not required for the mask returned by dma_get_required_mask() to be > 32-bit, so unless your card does support DAC (and everything so far shows > it does not), it will still fail on another platform where the function > does return a mask beyond 32 bits. > I guess that's right, It might still break then if DMA_BIT_MASK is set > 32bits on other platforms > Are you able to verify your card with a non-Alpha system that has memory > beyond the low 32-bit DMA space? I guess not, or you'd have done that > already, wouldn't you? > No, I don't, my other systems are either PCIe or have less than 4GB RAM. I might be able to get my hands on a HP Z440 which I've been told has one 32-bit PCI slot. > If you really wanted to double-check your Alpha correctly supports DAC, > you could try wiring your ISP1080 device temporarily via a 32-bit PCI > riser adapter (or an external 32-bit PCI enclosure) so as to force 64-bit > addressing via AD[31:0] lines only (assuming that ISP1080 got DAC support > right though).
