On Wed, Dec 16, 2009 at 03:04:03PM -0800, Roland Dreier wrote: > > > from a kexec point of view I believe that the preferred option is the > > former - shutdown the device so it can be initialised using standard paths > > in the second kernel. > > OK... however I'm not suggesting a separate kexec initialization path, > simply adding a reset of the device in the standard initialization. > This would be fairly normal for other types of device; for example, the > BIOS may have left a NIC in an undefined state due to network boot. Of > course BIOS is unlikely to use an IOAT DMA engine but the principle of > limiting assumptions about platform state still stands I think. If its reset in a standard path, then yes that seems sensible to me. I'm mainly concerned about avoiding something along the lines of: if (is_booting_from_kexec) reset_hw(); > >From a quick look, it seems tricky to get a clean shutdown of IOAT stuff > since there doesn't seem to be a clean ordering that makes sure the > ioatdma stuff is shutdown after everything using it. > > - R. > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
