From ae69e1eddc646ff8dc1d5439005d1f82c33f9ae7 Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan Date: Fri, 10 Jan 2014 15:09:38 -0800 Subject: [PATCH] Revert "powerpc/pseries/iommu: remove default window before attempting DDW manipulation" Ben rightfully pointed out that there is a race in the "newer" DDW code. Presuming we are running on recent enough firmware that supports the "reset" DDW manipulation call, we currently always remove the base 32-bit DMA window in order to maximize the resources for Phyp when creating the 64-bit window. However, this can be problematic for the case where multiple functions are in the same PE (partitionable endpoint), where some funtions might be 32-bit DMA only. All of a sudden, the only functional DMA window for such functions is gone. We will have serious errors in such situations. The best solution is simply to revert the extension to the DDW code where we ever remove the base DMA window. This reverts commit 25ebc45b93452d0bc60271f178237123c4b26808. Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt --- Reading git-format-patch failed