aic7xxx strange code

[Arjan van de Ven <arjanv@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1499 bytes --]

Hi,


the snippet below (from aic7xxx driver) is rather strange and probably
broken:

        /*
         * Although we can dma data above 4GB, our
         * "consistent" memory is below 4GB for
         * space efficiency reasons (only need a 4byte
         * address).  For this reason, we have to reset
         * our dma mask when doing allocations.
         */
        if (ahc->dev_softc != NULL)
                if (ahc_pci_set_dma_mask(ahc->dev_softc, 0xFFFFFFFF)) {
                        printk(KERN_WARNING "aic7xxx: No suitable DMA
available.\n");
                        return (ENODEV);
                }
        *vaddr = pci_alloc_consistent(ahc->dev_softc,
                                      dmat->maxsize, &map->bus_addr);
        if (ahc->dev_softc != NULL)
                if (ahc_pci_set_dma_mask(ahc->dev_softc,
                                     ahc->platform_data->hw_dma_mask)) {
                        printk(KERN_WARNING "aic7xxx: No suitable DMA
available.\n");
                        return (ENODEV);
                }


consistent memory ALWAYS comes from lower 4Gb regardless of the
pci_set_dma_mask() setting; only the pci_set_consistent_dma_mask()
function controls where consistent memory comes from, even in 2.4.0
already (which the ifdef surrounding this code tests for)

Justin: are you willing to just remove the unneeded dma mask sets? They
can race etc etc and are 100% unneeded.

Greetings,
   Arjan van de Ven

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]