On Thu, Nov 02, 2006 at 05:41:28AM -0700, Matthew Wilcox wrote: > On Wed, Nov 01, 2006 at 05:33:58PM -0800, Randy Dunlap wrote: > > unchecked_isa_dma - 1=>only use bottom 16 MB of ram (ISA DMA addressing > > restriction), 0=>can use full 32 bit (or better) DMA > > address space > > > > > It is hard for me to see why BusLogic controller would only do DMA > > > in low 16MB. Is there a fix for this? > > > > Does anyone know that controller hardware and its limitations? > > I don't, but: > > if (pci_set_dma_mask(PCI_Device, DMA_32BIT_MASK )) > continue; > > So somebody thinks the device can do 32-bit addressing. I would expect > that setting unchecked_isa_dma is a historical mistake. However, I > don't have any cards of this type to test. The buslogic driver also supports non-PCI devices, and at least the ISA boards have the obvious limitiation that unchecked_isa_dma = 1 caters to. Now someone would have to audit the driver whether it's enough to only set this on the actual isa hosts instead of the host template. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
