FAILED: patch "[PATCH] drm/gud: fix NULL crtc dereference on display disable" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] drm/gud: fix NULL crtc dereference on display disable" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 7149be786da012afc6bae293d38f8c1fff1fb90d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026031703-footpad-unpaved-0a7a@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7149be786da012afc6bae293d38f8c1fff1fb90d Mon Sep 17 00:00:00 2001
From: Shenghao Yang <me@shenghaoyang.info>
Date: Sun, 22 Feb 2026 13:45:51 +0800
Subject: [PATCH] drm/gud: fix NULL crtc dereference on display disable

gud_plane_atomic_update() currently handles both crtc state and
framebuffer updates - the complexity has led to a few accidental
NULL pointer dereferences.

Commit dc2d5ddb193e ("drm/gud: fix NULL fb and crtc dereferences
on USB disconnect") [1] fixed an earlier dereference but planes
can also be disabled in non-hotplug paths (e.g. display disables
via the desktop environment). The drm_dev_enter() call would not
cause an early return in those and subsequently oops on
dereferencing crtc:

BUG: kernel NULL pointer dereference, address: 00000000000005c8
CPU: 6 UID: 1000 PID: 3473 Comm: kwin_wayland Not tainted 6.18.2-200.vanilla.gud.fc42.x86_64 #1 PREEMPT(lazy)
RIP: 0010:gud_plane_atomic_update+0x148/0x470 [gud]
 <TASK>
 drm_atomic_helper_commit_planes+0x28e/0x310
 drm_atomic_helper_commit_tail+0x2a/0x70
 commit_tail+0xf1/0x150
 drm_atomic_helper_commit+0x13c/0x180
 drm_atomic_commit+0xb1/0xe0
info ? __pfx___drm_printfn_info+0x10/0x10
 drm_mode_atomic_ioctl+0x70f/0x7c0
 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
 drm_ioctl_kernel+0xae/0x100
 drm_ioctl+0x2a8/0x550
 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
 __x64_sys_ioctl+0x97/0xe0
 do_syscall_64+0x7e/0x7f0
 ? __ct_user_enter+0x56/0xd0
 ? do_syscall_64+0x158/0x7f0
 ? __ct_user_enter+0x56/0xd0
 ? do_syscall_64+0x158/0x7f0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Split out crtc handling from gud_plane_atomic_update() into
atomic_enable() and atomic_disable() functions to delegate
crtc state transitioning work to the DRM helpers.

To preserve the gud state commit sequence [2], switch to
the runtime PM version of drm_atomic_helper_commit_tail() which
ensures that crtcs are enabled (hence sending the
GUD_REQ_SET_CONTROLLER_ENABLE and GUD_REQ_SET_DISPLAY_ENABLE
requests) before a framebuffer update is sent.

[1] https://lore.kernel.org/all/20251231055039.44266-1-me@shenghaoyang.info/
[2] https://github.com/notro/gud/wiki/GUD-Protocol#display-state

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202601142159.0v8ilfVs-lkp@intel.com/
Fixes: 73cfd166e045 ("drm/gud: Replace simple display pipe with DRM atomic helpers")
Cc: <stable@vger.kernel.org> # 6.19.x
Cc: <stable@vger.kernel.org> # 6.18.x
Signed-off-by: Shenghao Yang <me@shenghaoyang.info>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Ruben Wauters <rubenru09@aol.com>
Signed-off-by: Ruben Wauters <rubenru09@aol.com>
Link: https://patch.msgid.link/20260222054551.80864-1-me@shenghaoyang.info

diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index d0122d477610..17c2dead2c13 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -339,7 +339,9 @@ static int gud_stats_debugfs(struct seq_file *m, void *data)
 }
 
 static const struct drm_crtc_helper_funcs gud_crtc_helper_funcs = {
-	.atomic_check = drm_crtc_helper_atomic_check
+	.atomic_check = drm_crtc_helper_atomic_check,
+	.atomic_enable = gud_crtc_atomic_enable,
+	.atomic_disable = gud_crtc_atomic_disable,
 };
 
 static const struct drm_crtc_funcs gud_crtc_funcs = {
@@ -364,6 +366,10 @@ static const struct drm_plane_funcs gud_plane_funcs = {
 	DRM_GEM_SHADOW_PLANE_FUNCS,
 };
 
+static const struct drm_mode_config_helper_funcs gud_mode_config_helpers = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
 static const struct drm_mode_config_funcs gud_mode_config_funcs = {
 	.fb_create = drm_gem_fb_create_with_dirty,
 	.atomic_check = drm_atomic_helper_check,
@@ -499,6 +505,7 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	drm->mode_config.min_height = le32_to_cpu(desc.min_height);
 	drm->mode_config.max_height = le32_to_cpu(desc.max_height);
 	drm->mode_config.funcs = &gud_mode_config_funcs;
+	drm->mode_config.helper_private = &gud_mode_config_helpers;
 
 	/* Format init */
 	formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
diff --git a/drivers/gpu/drm/gud/gud_internal.h b/drivers/gpu/drm/gud/gud_internal.h
index d27c31648341..8eec8335f5f9 100644
--- a/drivers/gpu/drm/gud/gud_internal.h
+++ b/drivers/gpu/drm/gud/gud_internal.h
@@ -62,6 +62,10 @@ int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val);
 
 void gud_clear_damage(struct gud_device *gdrm);
 void gud_flush_work(struct work_struct *work);
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_state *state);
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_state *state);
 int gud_plane_atomic_check(struct drm_plane *plane,
 			   struct drm_atomic_state *state);
 void gud_plane_atomic_update(struct drm_plane *plane,
diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
index 4b77be94348d..b355bf4d3389 100644
--- a/drivers/gpu/drm/gud/gud_pipe.c
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -580,6 +580,39 @@ int gud_plane_atomic_check(struct drm_plane *plane,
 	return ret;
 }
 
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_state *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
+	gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 1);
+
+	drm_dev_exit(idx);
+}
+
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_state *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
+
+	drm_dev_exit(idx);
+}
+
 void gud_plane_atomic_update(struct drm_plane *plane,
 			     struct drm_atomic_state *atomic_state)
 {
@@ -607,24 +640,12 @@ void gud_plane_atomic_update(struct drm_plane *plane,
 		mutex_unlock(&gdrm->damage_lock);
 	}
 
-	if (!drm_dev_enter(drm, &idx))
+	if (!crtc || !drm_dev_enter(drm, &idx))
 		return;
 
-	if (!old_state->fb)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
-
-	if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
-		gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
-
-	if (crtc->state->active_changed)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
-
-	if (!fb)
-		goto ctrl_disable;
-
 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 	if (ret)
-		goto ctrl_disable;
+		goto out;
 
 	drm_atomic_helper_damage_iter_init(&iter, old_state, new_state);
 	drm_atomic_for_each_plane_damage(&iter, &damage)
@@ -632,9 +653,6 @@ void gud_plane_atomic_update(struct drm_plane *plane,
 
 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 
-ctrl_disable:
-	if (!crtc->state->enable)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
-
+out:
 	drm_dev_exit(idx);
 }

[PATCH 6.18.y 1/2] drm/gud: rearrange gud_probe() to prepare for function splitting

[Sasha Levin]

From: Ruben Wauters <rubenru09@aol.com>

[ Upstream commit b9e5e9d2c187b849e050d59823e8c834f78475ab ]

gud_probe() is currently very large and does many things, including
pipeline setup and feature detection, as well as having USB functions.

This patch re-orders the code in gud_probe() to make it more organised
and easier to split apart in the future.

Signed-off-by: Ruben Wauters <rubenru09@aol.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20251020140147.5017-1-rubenru09@aol.com/
Stable-dep-of: 7149be786da0 ("drm/gud: fix NULL crtc dereference on display disable")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/gud/gud_drv.c | 45 +++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index b7345c8d823de..42135a48d92ef 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -249,7 +249,7 @@ int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val)
 	return gud_usb_set(gdrm, request, 0, &val, sizeof(val));
 }
 
-static int gud_get_properties(struct gud_device *gdrm)
+static int gud_plane_add_properties(struct gud_device *gdrm)
 {
 	struct gud_property_req *properties;
 	unsigned int i, num_properties;
@@ -463,10 +463,6 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 		return PTR_ERR(gdrm);
 
 	drm = &gdrm->drm;
-	drm->mode_config.funcs = &gud_mode_config_funcs;
-	ret = drmm_mode_config_init(drm);
-	if (ret)
-		return ret;
 
 	gdrm->flags = le32_to_cpu(desc.flags);
 	gdrm->compression = desc.compression & GUD_COMPRESSION_LZ4;
@@ -483,11 +479,28 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	if (ret)
 		return ret;
 
+	usb_set_intfdata(intf, gdrm);
+
+	dma_dev = usb_intf_get_dma_device(intf);
+	if (dma_dev) {
+		drm_dev_set_dma_dev(drm, dma_dev);
+		put_device(dma_dev);
+	} else {
+		dev_warn(dev, "buffer sharing not supported"); /* not an error */
+	}
+
+	/* Mode config init */
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ret;
+
 	drm->mode_config.min_width = le32_to_cpu(desc.min_width);
 	drm->mode_config.max_width = le32_to_cpu(desc.max_width);
 	drm->mode_config.min_height = le32_to_cpu(desc.min_height);
 	drm->mode_config.max_height = le32_to_cpu(desc.max_height);
+	drm->mode_config.funcs = &gud_mode_config_funcs;
 
+	/* Format init */
 	formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
 	/* Add room for emulated XRGB8888 */
 	formats = devm_kmalloc_array(dev, GUD_FORMATS_MAX_NUM + 1, sizeof(*formats), GFP_KERNEL);
@@ -587,6 +600,7 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 			return -ENOMEM;
 	}
 
+	/* Pipeline init */
 	ret = drm_universal_plane_init(drm, &gdrm->plane, 0,
 				       &gud_plane_funcs,
 				       formats, num_formats,
@@ -598,12 +612,9 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	drm_plane_helper_add(&gdrm->plane, &gud_plane_helper_funcs);
 	drm_plane_enable_fb_damage_clips(&gdrm->plane);
 
-	devm_kfree(dev, formats);
-	devm_kfree(dev, formats_dev);
-
-	ret = gud_get_properties(gdrm);
+	ret = gud_plane_add_properties(gdrm);
 	if (ret) {
-		dev_err(dev, "Failed to get properties (error=%d)\n", ret);
+		dev_err(dev, "Failed to add properties (error=%d)\n", ret);
 		return ret;
 	}
 
@@ -621,16 +632,7 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	}
 
 	drm_mode_config_reset(drm);
-
-	usb_set_intfdata(intf, gdrm);
-
-	dma_dev = usb_intf_get_dma_device(intf);
-	if (dma_dev) {
-		drm_dev_set_dma_dev(drm, dma_dev);
-		put_device(dma_dev);
-	} else {
-		dev_warn(dev, "buffer sharing not supported"); /* not an error */
-	}
+	drm_kms_helper_poll_init(drm);
 
 	drm_debugfs_add_file(drm, "stats", gud_stats_debugfs, NULL);
 
@@ -638,7 +640,8 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	if (ret)
 		return ret;
 
-	drm_kms_helper_poll_init(drm);
+	devm_kfree(dev, formats);
+	devm_kfree(dev, formats_dev);
 
 	drm_client_setup(drm, NULL);
 
-- 
2.51.0

[PATCH 6.18.y 2/2] drm/gud: fix NULL crtc dereference on display disable

[Sasha Levin]

From: Shenghao Yang <me@shenghaoyang.info>

[ Upstream commit 7149be786da012afc6bae293d38f8c1fff1fb90d ]

gud_plane_atomic_update() currently handles both crtc state and
framebuffer updates - the complexity has led to a few accidental
NULL pointer dereferences.

Commit dc2d5ddb193e ("drm/gud: fix NULL fb and crtc dereferences
on USB disconnect") [1] fixed an earlier dereference but planes
can also be disabled in non-hotplug paths (e.g. display disables
via the desktop environment). The drm_dev_enter() call would not
cause an early return in those and subsequently oops on
dereferencing crtc:

BUG: kernel NULL pointer dereference, address: 00000000000005c8
CPU: 6 UID: 1000 PID: 3473 Comm: kwin_wayland Not tainted 6.18.2-200.vanilla.gud.fc42.x86_64 #1 PREEMPT(lazy)
RIP: 0010:gud_plane_atomic_update+0x148/0x470 [gud]
 <TASK>
 drm_atomic_helper_commit_planes+0x28e/0x310
 drm_atomic_helper_commit_tail+0x2a/0x70
 commit_tail+0xf1/0x150
 drm_atomic_helper_commit+0x13c/0x180
 drm_atomic_commit+0xb1/0xe0
info ? __pfx___drm_printfn_info+0x10/0x10
 drm_mode_atomic_ioctl+0x70f/0x7c0
 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
 drm_ioctl_kernel+0xae/0x100
 drm_ioctl+0x2a8/0x550
 ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
 __x64_sys_ioctl+0x97/0xe0
 do_syscall_64+0x7e/0x7f0
 ? __ct_user_enter+0x56/0xd0
 ? do_syscall_64+0x158/0x7f0
 ? __ct_user_enter+0x56/0xd0
 ? do_syscall_64+0x158/0x7f0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Split out crtc handling from gud_plane_atomic_update() into
atomic_enable() and atomic_disable() functions to delegate
crtc state transitioning work to the DRM helpers.

To preserve the gud state commit sequence [2], switch to
the runtime PM version of drm_atomic_helper_commit_tail() which
ensures that crtcs are enabled (hence sending the
GUD_REQ_SET_CONTROLLER_ENABLE and GUD_REQ_SET_DISPLAY_ENABLE
requests) before a framebuffer update is sent.

[1] https://lore.kernel.org/all/20251231055039.44266-1-me@shenghaoyang.info/
[2] https://github.com/notro/gud/wiki/GUD-Protocol#display-state

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202601142159.0v8ilfVs-lkp@intel.com/
Fixes: 73cfd166e045 ("drm/gud: Replace simple display pipe with DRM atomic helpers")
Cc: <stable@vger.kernel.org> # 6.19.x
Cc: <stable@vger.kernel.org> # 6.18.x
Signed-off-by: Shenghao Yang <me@shenghaoyang.info>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Ruben Wauters <rubenru09@aol.com>
Signed-off-by: Ruben Wauters <rubenru09@aol.com>
Link: https://patch.msgid.link/20260222054551.80864-1-me@shenghaoyang.info
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/gud/gud_drv.c      |  9 ++++-
 drivers/gpu/drm/gud/gud_internal.h |  4 +++
 drivers/gpu/drm/gud/gud_pipe.c     | 54 ++++++++++++++++++++----------
 3 files changed, 48 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
index 42135a48d92ef..a2000991ecbe4 100644
--- a/drivers/gpu/drm/gud/gud_drv.c
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -339,7 +339,9 @@ static int gud_stats_debugfs(struct seq_file *m, void *data)
 }
 
 static const struct drm_crtc_helper_funcs gud_crtc_helper_funcs = {
-	.atomic_check = drm_crtc_helper_atomic_check
+	.atomic_check = drm_crtc_helper_atomic_check,
+	.atomic_enable = gud_crtc_atomic_enable,
+	.atomic_disable = gud_crtc_atomic_disable,
 };
 
 static const struct drm_crtc_funcs gud_crtc_funcs = {
@@ -364,6 +366,10 @@ static const struct drm_plane_funcs gud_plane_funcs = {
 	DRM_GEM_SHADOW_PLANE_FUNCS,
 };
 
+static const struct drm_mode_config_helper_funcs gud_mode_config_helpers = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
 static const struct drm_mode_config_funcs gud_mode_config_funcs = {
 	.fb_create = drm_gem_fb_create_with_dirty,
 	.atomic_check = drm_atomic_helper_check,
@@ -499,6 +505,7 @@ static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	drm->mode_config.min_height = le32_to_cpu(desc.min_height);
 	drm->mode_config.max_height = le32_to_cpu(desc.max_height);
 	drm->mode_config.funcs = &gud_mode_config_funcs;
+	drm->mode_config.helper_private = &gud_mode_config_helpers;
 
 	/* Format init */
 	formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
diff --git a/drivers/gpu/drm/gud/gud_internal.h b/drivers/gpu/drm/gud/gud_internal.h
index d27c31648341c..8eec8335f5f90 100644
--- a/drivers/gpu/drm/gud/gud_internal.h
+++ b/drivers/gpu/drm/gud/gud_internal.h
@@ -62,6 +62,10 @@ int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val);
 
 void gud_clear_damage(struct gud_device *gdrm);
 void gud_flush_work(struct work_struct *work);
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_state *state);
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_state *state);
 int gud_plane_atomic_check(struct drm_plane *plane,
 			   struct drm_atomic_state *state);
 void gud_plane_atomic_update(struct drm_plane *plane,
diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
index cfd66c879ae40..0d38eecd152da 100644
--- a/drivers/gpu/drm/gud/gud_pipe.c
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -580,6 +580,39 @@ int gud_plane_atomic_check(struct drm_plane *plane,
 	return ret;
 }
 
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_state *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
+	gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 1);
+
+	drm_dev_exit(idx);
+}
+
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_state *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
+
+	drm_dev_exit(idx);
+}
+
 void gud_plane_atomic_update(struct drm_plane *plane,
 			     struct drm_atomic_state *atomic_state)
 {
@@ -607,24 +640,12 @@ void gud_plane_atomic_update(struct drm_plane *plane,
 		mutex_unlock(&gdrm->damage_lock);
 	}
 
-	if (!drm_dev_enter(drm, &idx))
+	if (!crtc || !drm_dev_enter(drm, &idx))
 		return;
 
-	if (!old_state->fb)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
-
-	if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
-		gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
-
-	if (crtc->state->active_changed)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
-
-	if (!fb)
-		goto ctrl_disable;
-
 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 	if (ret)
-		goto ctrl_disable;
+		goto out;
 
 	drm_atomic_helper_damage_iter_init(&iter, old_state, new_state);
 	drm_atomic_for_each_plane_damage(&iter, &damage)
@@ -632,9 +653,6 @@ void gud_plane_atomic_update(struct drm_plane *plane,
 
 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 
-ctrl_disable:
-	if (!crtc->state->enable)
-		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
-
+out:
 	drm_dev_exit(idx);
 }
-- 
2.51.0