Messages in this thread | | | Subject | Re: [PATCH] 2.4 use __dma_buffer in scsi.h | Date | Thu, 13 Jun 2002 13:52:39 -0400 | From | James Bottomley <> |
| |
roland@topspin.com said: > Out of curiousity, how do you deal with someone writing to Scsi_Cmnd > _before_ the DMA and having that data lost when pci_map_single() with > PCI_DMA_FROMDEVICE invalidates the cache before writeback?
The the pci_map_single with PCI_DMA_FROMDEVICE is supposed to do a writeback invalidate cycle on the cache when pci_sync_single is called (at least this is how it is implemented on parisc) so any writes up to the sync point are flushed to memory before the cache line is trashed.
James
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |