From b1d0b34b748c9e5e67a91c545cb48711cfde119c Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Sat, 17 Mar 2018 01:52:38 +0100 Subject: [PATCH] drm/tegra: dc: Detach IOMMU group from domain only once Detaching from an IOMMU group multiple times can lead to a crash. This could potentially be fixed in the IOMMU driver, but it's easy to avoid the subsequent detach operations in this driver, so do that as well. Signed-off-by: Thierry Reding --- drivers/gpu/drm/tegra/dc.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index b8403ed48285..fbffe1948b3b 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -1903,8 +1903,12 @@ cleanup: if (!IS_ERR(primary)) drm_plane_cleanup(primary); - if (group && tegra->domain) { - iommu_detach_group(tegra->domain, group); + if (group && dc->domain) { + if (group == tegra->group) { + iommu_detach_group(dc->domain, group); + tegra->group = NULL; + } + dc->domain = NULL; } @@ -1913,8 +1917,10 @@ cleanup: static int tegra_dc_exit(struct host1x_client *client) { + struct drm_device *drm = dev_get_drvdata(client->parent); struct iommu_group *group = iommu_group_get(client->dev); struct tegra_dc *dc = host1x_client_to_dc(client); + struct tegra_drm *tegra = drm->dev_private; int err; devm_free_irq(dc->dev, dc->irq, dc); @@ -1926,7 +1932,11 @@ static int tegra_dc_exit(struct host1x_client *client) } if (group && dc->domain) { - iommu_detach_group(dc->domain, group); + if (group == tegra->group) { + iommu_detach_group(dc->domain, group); + tegra->group = NULL; + } + dc->domain = NULL; } -- 2.30.2