diff mbox series

[drm-misc-next,8/8] drm/arm/malidp: drv: protect device resources after removal

Message ID 20220819212538.559902-2-dakr@redhat.com (mailing list archive)
State New, archived
Headers show
Series drm/arm/malidp: use drm managed resources | expand

Commit Message

Danilo Krummrich Aug. 19, 2022, 9:25 p.m. UTC
(Hardware) resources which are bound to the driver and device lifecycle
must not be accessed after the device and driver are unbound.

However, the DRM device isn't freed as long as the last user didn't
close it, hence userspace can still call into the driver.

Therefore protect the critical sections which are accessing those
resources with drm_dev_enter() and drm_dev_exit().

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
---
 drivers/gpu/drm/arm/malidp_drv.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index aedd30f5f451..8bb8e8d14461 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -234,9 +234,12 @@  static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
 	struct malidp_drm *malidp = drm_to_malidp(drm);
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state;
-	int i;
+	int i, idx;
 	bool fence_cookie = dma_fence_begin_signalling();
 
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
 	pm_runtime_get_sync(drm->dev);
 
 	/*
@@ -267,6 +270,8 @@  static void malidp_atomic_commit_tail(struct drm_atomic_state *state)
 	pm_runtime_put(drm->dev);
 
 	drm_atomic_helper_cleanup_planes(drm, state);
+
+	drm_dev_exit(idx);
 }
 
 static const struct drm_mode_config_helper_funcs malidp_mode_config_helpers = {