> From: Martin Diehl <[EMAIL PROTECTED]> > To: David Brownell <[EMAIL PROTECTED]> > cc: Georg Acher <[EMAIL PROTECTED]>, [EMAIL PROTECTED] > Date: Thu, 19 Apr 2001 15:17:25 +0200 (CEST) > What I mean is something like > > *buffer = 0x12345f00; > dma_addr = pci_map_single(dev,buffer,len,PCI_DMA_TODEVICE); > pci_write_config_dword(dev,reg,dma_addr); > > If caching is write-back my feeling is there is nothing that guarantees > the modification went to physmem before the device starts reading from it. Exactly. That's why you must call pci_dma_sync_single before the transfer, if you used pci_map_single. > So there might be another requirement for the buffer being passed to > pci_map_single(): caller must have caching disabled. No. You mix consistent and streamed mappings. > Comments? Did I miss something? Why don't you RTFM Documentation/DMA-mapping.txt? It's all there. -- Pete _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: http://lists.sourceforge.net/lists/listinfo/linux-usb-devel
