This is simplest solution about reported problem[1]. It's no problem to clear channel only when iommu is enabled, if we consider that we cannot recognize iommu errors when iommu is disabled and it have been valid until now. But this cannot be nice solution.
[1] https://lkml.org/lkml/2015/7/21/404 Signed-off-by: Joonyoung Shim <jy0922.shim at samsung.com> --- drivers/gpu/drm/exynos/exynos_drm_fimd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index 8d362b9..337af02 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -956,7 +956,8 @@ static int fimd_bind(struct device *dev, struct device *master, void *data) if (ctx->display) exynos_drm_create_enc_conn(drm_dev, ctx->display); - fimd_clear_channels(ctx->crtc); + if (is_drm_iommu_supported(drm_dev)) + fimd_clear_channels(ctx->crtc); ret = drm_iommu_attach_device(drm_dev, dev); if (ret) -- 1.9.1
