On Thu, Jan 15, 2009 at 11:53:24PM +0100, Arnd Bergmann wrote: > On Thursday 15 January 2009, Ira Snyder wrote: > > I do have mailboxes (two inbound, two outbound) which can generate > > interrupts, as well as doorbell registers (one inbound, one outbound). > > The doorbell register's bits are "write 1 to clear", and can only be > > cleared by the opposite side. > > > > Ok, in this case, you should be able to use one of these to implement > the DMA complete interrupt, but adding an extra DMA transfer to the > mailbox after each transfer that you want to get notified for.
Yep. I wouldn't have come up with that idea on my own, but it seems obvious now :) It seems a little strange to keep the DMA descriptors host memory (the DMA controller will need to issue a PCI read to get them) but I guess that is how real network cards work. Thanks, Ira _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
