~amjoseph/ownerboot

0bb8bac4a224e3fb7dc7197dcddaa2236e548799 — Adam Joseph 4 months ago 9b88efd
kevin/linux.config: comments explaining importance of CONFIG_ARM_DMA_USE_IOMMU

If `CONFIG_ARM_DMA_USE_IOMMU` is not enabled, the `panfrost` driver
will fail to create several of the /dev/dri nodes.  The failure mode
this induces on wlroots-based compositors is extremely painful and
difficult to troubleshoot; wlroots gives you absolutely no clue
what's gone wrong.
2 files changed, 4 insertions(+), 1 deletions(-)

M src/platform/kevin/default.nix
M src/platform/kevin/linux.config
M src/platform/kevin/default.nix => src/platform/kevin/default.nix +2 -0
@@ 60,6 60,8 @@ in {

    kernel =
      final.lib.makeOverridable (prev.kernel.override {
        # Note: without `ARM_DMA_USE_IOMMU=y`, panfrost will not
        # create /dev/dri/render*
        config = ./linux.config;
        buildTargets = [ "Image" "dtbs" ];
      }).overrideAttrs (a: {

M src/platform/kevin/linux.config => src/platform/kevin/linux.config +2 -1
@@ 8005,4 8005,5 @@ CONFIG_MEMTEST=y
# end of Kernel hacking


CONFIG_ARM_DMA_USE_IOMMU=y
\ No newline at end of file
# without this panfrost will not create /dev/dri/render*
CONFIG_ARM_DMA_USE_IOMMU=y