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 <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index b8403ed..fbffe19 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1903,8 +1903,12 @@ static int tegra_dc_init(struct host1x_client *client)
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 @@ static int tegra_dc_init(struct host1x_client *client)
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;
}