On Gwe, 2005-07-08 at 09:18, Thomas Hellström wrote: > Is this because they are not physically contigous or because they may not > be accessible to the PCI device? I was thinking of using vmalloced memory > instead of kmalloced for the device sg-list, and since it is a linked list > it should be able to deal with non-contigous pages.
It may not be physically accessible. The dma allocation functions should be used to reliably allocate DMA spaces. > Preferrably I'd like to have an implementation where one can start a DMA > bitblt operation then return to whatever is being done at the moment, and > a sync function called to make sure the DMA has finished. This will > require, however, a small sg-list / page pointer array ring buffer and > that all free() and unlock operations can be done from the DMA complete > interrupt handler. This is near enough how video4linux works except that it uses a ring buffer rather than keep freeing (as its TV capture) so only does the pci write to stop, read to avoid posting and free at close time. Alan ------------------------------------------------------- This SF.Net email is sponsored by the 'Do More With Dual!' webinar happening July 14 at 8am PDT/11am EDT. We invite you to explore the latest in dual core and dual graphics technology at this free one hour event hosted by HP, AMD, and NVIDIA. To register visit http://www.hp.com/go/dualwebinar -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
