drm: Add GUD USB Display driver

This adds a USB display driver with the intention that it can be
used with future USB interfaced low end displays/adapters. The Linux
gadget device driver will serve as the canonical device implementation.

The following DRM properties are supported:
- Plane rotation
- Connector TV properties

There is also support for backlight brightness exposed as a backlight
device.

Display modes can be made available to the host driver either as DRM
display modes or through EDID. If both are present, EDID is just passed
on to userspace.

Performance is preferred over color depth, so if the device supports
RGB565, DRM_CAP_DUMB_PREFERRED_DEPTH will return 16.

If the device transfer buffer can't fit an uncompressed framebuffer
update, the update is split up into parts that do fit.

Optimal user experience is achieved by providing damage reports either by
setting FB_DAMAGE_CLIPS on pageflips or calling DRM_IOCTL_MODE_DIRTYFB.

LZ4 compression is used if the device supports it.

The driver supports a one bit monochrome transfer format: R1. This is not
implemented in the gadget driver. It is added in preparation for future
monochrome e-ink displays.

The driver is MIT licensed to smooth the path for any BSD port of the
driver.

v2:
- Use devm_drm_dev_alloc() and drmm_mode_config_init()
- drm_fbdev_generic_setup: Use preferred_bpp=0, 16 was a copy paste error
- The drm_backlight_helper is dropped, copy in the code
- Support protocol version backwards compatibility for device

v3:
- Use donated Openmoko USB pid
- Use direct compression from framebuffer when pitch matches, not only on
  full frames, so split updates can benefit
- Use __le16 in struct gud_drm_req_get_connector_status
- Set edid property when the device only provides edid
- Clear compression fields in struct gud_drm_req_set_buffer
- Fix protocol version negotiation
- Remove mode->vrefresh, it's calculated

v4:
- Drop the status req polling which was a workaround for something that
  turned out to be a dwc2 udc driver problem
- Add a flag for the Linux gadget to require a status request on
  SET operations. Other devices will only get status req on STALL errors
- Use protocol specific error codes (Peter)
- Add a flag for devices that want to receive the entire framebuffer on
  each flush (Lubomir)
- Retry a failed framebuffer flush
- If mode has changed wait for worker and clear pending damage before
  queuing up new damage, fb width/height might have changed
- Increase error counter on bulk transfer failures
- Use DRM_MODE_CONNECTOR_USB
- Handle R1 kmalloc error (Peter)
- Don't try and replicate the USB get descriptor request standard for the
  display descriptor (Peter)
- Make max_buffer_size optional (Peter), drop the pow2 requirement since
  it's not necessary anymore.
- Don't pre-alloc a control request buffer, it was only 4k
- Let gud.h describe the whole protocol explicitly and don't let DRM
  leak into it (Peter)
- Drop display mode .hskew and .vscan from the protocol
- Shorten names: s/GUD_DRM_/GUD_/ s/gud_drm_/gud_/ (Peter)
- Fix gud_pipe_check() connector picking when switching connector
- Drop gud_drm_driver_gem_create_object() cached is default now
- Retrieve USB device from struct drm_device.dev instead of keeping a
  pointer
- Honour fb->offsets[0]
- Fix mode fetching when connector status is forced
- Check EDID length reported by the device
- Use drm_do_get_edid() so userspace can overrride EDID
- Set epoch counter to signal connector status change
- gud_drm_driver can be const now

v5:
- GUD_DRM_FORMAT_R1: Use non-human ascii values (Daniel)
- Change name to: GUD USB Display (Thomas, Simon)
- Change one __u32 -> __le32 in protocol header
- Always log fb flush errors, unless the previous one failed
- Run backlight update in a worker to avoid upsetting lockdep (Daniel)
- Drop backlight_ops.get_brightness, there's no readback from the device
  so it doesn't really add anything.
- Set dma mask, needed by dma-buf importers

v6:
- Use obj-y in Makefile (Peter)
- Fix missing le32_to_cpu() when using GUD_DISPLAY_MAGIC (Peter)
- Set initial brightness on backlight device

v7:
- LZ4_compress_default() can return zero, check for that
- Fix memory leak in gud_pipe_check() error path (Peter)
- Improve debug and error messages (Peter)
- Don't pass length in protocol structs (Peter)
- Pass USB interface to gud_usb_control_msg() et al. (Peter)
- Improve gud_connector_fill_properties() (Peter)
- Add GUD_PIXEL_FORMAT_RGB111 (Peter)
- Remove GUD_REQ_SET_VERSION (Peter)
- Fix DRM_IOCTL_MODE_OBJ_SETPROPERTY and the rotation property
- Fix dma-buf import (Thomas)

v8:
- Forgot to filter RGB111 from reaching userspace
- Handle a device that only returns unknown device properties (Peter)
- s/GUD_PIXEL_FORMAT_RGB111/GUD_PIXEL_FORMAT_XRGB1111/ (Peter)
- Fix R1 and XRGB1111 format conversion
- Add FIXME about Big Endian being broken (Peter, Ilia)

Cc: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Peter Stuge <peter@stuge.se>
Tested-by: Peter Stuge <peter@stuge.se>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210313112545.37527-4-noralf@tronnes.org

1 files changed, 552 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
new file mode 100644
index 000000000000..ab96afb94241
--- /dev/null
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -0,0 +1,552 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2020 Noralf Trønnes
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/lz4.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_print.h>
+#include <drm/drm_rect.h>
+#include <drm/drm_simple_kms_helper.h>
+#include <drm/gud.h>
+
+#include "gud_internal.h"
+
+/*
+ * FIXME: The driver is probably broken on Big Endian machines.
+ * See discussion:
+ * https://lore.kernel.org/dri-devel/CAKb7UvihLX0hgBOP3VBG7O+atwZcUVCPVuBdfmDMpg0NjXe-cQ@mail.gmail.com/
+ */
+
+static bool gud_is_big_endian(void)
+{
+#if defined(__BIG_ENDIAN)
+	return true;
+#else
+	return false;
+#endif
+}
+
+static size_t gud_xrgb8888_to_r124(u8 *dst, const struct drm_format_info *format,
+				   void *src, struct drm_framebuffer *fb,
+				   struct drm_rect *rect)
+{
+	unsigned int block_width = drm_format_info_block_width(format, 0);
+	unsigned int bits_per_pixel = 8 / block_width;
+	unsigned int x, y, width, height;
+	u8 pix, *pix8, *block = dst; /* Assign to silence compiler warning */
+	size_t len;
+	void *buf;
+
+	WARN_ON_ONCE(format->char_per_block[0] != 1);
+
+	/* Start on a byte boundary */
+	rect->x1 = ALIGN_DOWN(rect->x1, block_width);
+	width = drm_rect_width(rect);
+	height = drm_rect_height(rect);
+	len = drm_format_info_min_pitch(format, 0, width) * height;
+
+	buf = kmalloc(width * height, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	drm_fb_xrgb8888_to_gray8(buf, src, fb, rect);
+	pix8 = buf;
+
+	for (y = 0; y < height; y++) {
+		for (x = 0; x < width; x++) {
+			unsigned int pixpos = x % block_width; /* within byte from the left */
+			unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
+
+			if (!pixpos) {
+				block = dst++;
+				*block = 0;
+			}
+
+			pix = (*pix8++) >> (8 - bits_per_pixel);
+			*block |= pix << pixshift;
+		}
+	}
+
+	kfree(buf);
+
+	return len;
+}
+
+static size_t gud_xrgb8888_to_color(u8 *dst, const struct drm_format_info *format,
+				    void *src, struct drm_framebuffer *fb,
+				    struct drm_rect *rect)
+{
+	unsigned int block_width = drm_format_info_block_width(format, 0);
+	unsigned int bits_per_pixel = 8 / block_width;
+	u8 r, g, b, pix, *block = dst; /* Assign to silence compiler warning */
+	unsigned int x, y, width;
+	u32 *pix32;
+	size_t len;
+
+	/* Start on a byte boundary */
+	rect->x1 = ALIGN_DOWN(rect->x1, block_width);
+	width = drm_rect_width(rect);
+	len = drm_format_info_min_pitch(format, 0, width) * drm_rect_height(rect);
+
+	for (y = rect->y1; y < rect->y2; y++) {
+		pix32 = src + (y * fb->pitches[0]);
+		pix32 += rect->x1;
+
+		for (x = 0; x < width; x++) {
+			unsigned int pixpos = x % block_width; /* within byte from the left */
+			unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
+
+			if (!pixpos) {
+				block = dst++;
+				*block = 0;
+			}
+
+			r = *pix32 >> 16;
+			g = *pix32 >> 8;
+			b = *pix32++;
+
+			switch (format->format) {
+			case GUD_DRM_FORMAT_XRGB1111:
+				pix = ((r >> 7) << 2) | ((g >> 7) << 1) | (b >> 7);
+				break;
+			default:
+				WARN_ON_ONCE(1);
+				return len;
+			};
+
+			*block |= pix << pixshift;
+		}
+	}
+
+	return len;
+}
+
+static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			  const struct drm_format_info *format, struct drm_rect *rect,
+			  struct gud_set_buffer_req *req)
+{
+	struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach;
+	u8 compression = gdrm->compression;
+	struct dma_buf_map map;
+	void *vaddr, *buf;
+	size_t pitch, len;
+	int ret = 0;
+
+	pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(rect));
+	len = pitch * drm_rect_height(rect);
+	if (len > gdrm->bulk_len)
+		return -E2BIG;
+
+	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
+	if (ret)
+		return ret;
+
+	vaddr = map.vaddr + fb->offsets[0];
+
+	if (import_attach) {
+		ret = dma_buf_begin_cpu_access(import_attach->dmabuf, DMA_FROM_DEVICE);
+		if (ret)
+			goto vunmap;
+	}
+retry:
+	if (compression)
+		buf = gdrm->compress_buf;
+	else
+		buf = gdrm->bulk_buf;
+
+	/*
+	 * Imported buffers are assumed to be write-combined and thus uncached
+	 * with slow reads (at least on ARM).
+	 */
+	if (format != fb->format) {
+		if (format->format == GUD_DRM_FORMAT_R1) {
+			len = gud_xrgb8888_to_r124(buf, format, vaddr, fb, rect);
+			if (!len) {
+				ret = -ENOMEM;
+				goto end_cpu_access;
+			}
+		} else if (format->format == DRM_FORMAT_RGB565) {
+			drm_fb_xrgb8888_to_rgb565(buf, vaddr, fb, rect, gud_is_big_endian());
+		} else {
+			len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
+		}
+	} else if (gud_is_big_endian() && format->cpp[0] > 1) {
+		drm_fb_swab(buf, vaddr, fb, rect, !import_attach);
+	} else if (compression && !import_attach && pitch == fb->pitches[0]) {
+		/* can compress directly from the framebuffer */
+		buf = vaddr + rect->y1 * pitch;
+	} else {
+		drm_fb_memcpy(buf, vaddr, fb, rect);
+	}
+
+	memset(req, 0, sizeof(*req));
+	req->x = cpu_to_le32(rect->x1);
+	req->y = cpu_to_le32(rect->y1);
+	req->width = cpu_to_le32(drm_rect_width(rect));
+	req->height = cpu_to_le32(drm_rect_height(rect));
+	req->length = cpu_to_le32(len);
+
+	if (compression & GUD_COMPRESSION_LZ4) {
+		int complen;
+
+		complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
+		if (complen <= 0) {
+			compression = 0;
+			goto retry;
+		}
+
+		req->compression = GUD_COMPRESSION_LZ4;
+		req->compressed_length = cpu_to_le32(complen);
+	}
+
+end_cpu_access:
+	if (import_attach)
+		dma_buf_end_cpu_access(import_attach->dmabuf, DMA_FROM_DEVICE);
+vunmap:
+	drm_gem_shmem_vunmap(fb->obj[0], &map);
+
+	return ret;
+}
+
+static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			  const struct drm_format_info *format, struct drm_rect *rect)
+{
+	struct usb_device *usb = gud_to_usb_device(gdrm);
+	struct gud_set_buffer_req req;
+	int ret, actual_length;
+	size_t len, trlen;
+
+	drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
+
+	ret = gud_prep_flush(gdrm, fb, format, rect, &req);
+	if (ret)
+		return ret;
+
+	len = le32_to_cpu(req.length);
+
+	if (req.compression)
+		trlen = le32_to_cpu(req.compressed_length);
+	else
+		trlen = len;
+
+	gdrm->stats_length += len;
+	/* Did it wrap around? */
+	if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
+		gdrm->stats_length = len;
+		gdrm->stats_actual_length = 0;
+	}
+	gdrm->stats_actual_length += trlen;
+
+	if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
+		ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
+		if (ret)
+			return ret;
+	}
+
+	ret = usb_bulk_msg(usb, gdrm->bulk_pipe, gdrm->bulk_buf, trlen,
+			   &actual_length, msecs_to_jiffies(3000));
+	if (!ret && trlen != actual_length)
+		ret = -EIO;
+	if (ret)
+		gdrm->stats_num_errors++;
+
+	return ret;
+}
+
+void gud_clear_damage(struct gud_device *gdrm)
+{
+	gdrm->damage.x1 = INT_MAX;
+	gdrm->damage.y1 = INT_MAX;
+	gdrm->damage.x2 = 0;
+	gdrm->damage.y2 = 0;
+}
+
+static void gud_add_damage(struct gud_device *gdrm, struct drm_rect *damage)
+{
+	gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
+	gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
+	gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
+	gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
+}
+
+static void gud_retry_failed_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
+				   struct drm_rect *damage)
+{
+	/*
+	 * pipe_update waits for the worker when the display mode is going to change.
+	 * This ensures that the width and height is still the same making it safe to
+	 * add back the damage.
+	 */
+
+	mutex_lock(&gdrm->damage_lock);
+	if (!gdrm->fb) {
+		drm_framebuffer_get(fb);
+		gdrm->fb = fb;
+	}
+	gud_add_damage(gdrm, damage);
+	mutex_unlock(&gdrm->damage_lock);
+
+	/* Retry only once to avoid a possible storm in case of continues errors. */
+	if (!gdrm->prev_flush_failed)
+		queue_work(system_long_wq, &gdrm->work);
+	gdrm->prev_flush_failed = true;
+}
+
+void gud_flush_work(struct work_struct *work)
+{
+	struct gud_device *gdrm = container_of(work, struct gud_device, work);
+	const struct drm_format_info *format;
+	struct drm_framebuffer *fb;
+	struct drm_rect damage;
+	unsigned int i, lines;
+	int idx, ret = 0;
+	size_t pitch;
+
+	if (!drm_dev_enter(&gdrm->drm, &idx))
+		return;
+
+	mutex_lock(&gdrm->damage_lock);
+	fb = gdrm->fb;
+	gdrm->fb = NULL;
+	damage = gdrm->damage;
+	gud_clear_damage(gdrm);
+	mutex_unlock(&gdrm->damage_lock);
+
+	if (!fb)
+		goto out;
+
+	format = fb->format;
+	if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
+		format = gdrm->xrgb8888_emulation_format;
+
+	/* Split update if it's too big */
+	pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(&damage));
+	lines = drm_rect_height(&damage);
+
+	if (gdrm->bulk_len < lines * pitch)
+		lines = gdrm->bulk_len / pitch;
+
+	for (i = 0; i < DIV_ROUND_UP(drm_rect_height(&damage), lines); i++) {
+		struct drm_rect rect = damage;
+
+		rect.y1 += i * lines;
+		rect.y2 = min_t(u32, rect.y1 + lines, damage.y2);
+
+		ret = gud_flush_rect(gdrm, fb, format, &rect);
+		if (ret) {
+			if (ret != -ENODEV && ret != -ECONNRESET &&
+			    ret != -ESHUTDOWN && ret != -EPROTO) {
+				bool prev_flush_failed = gdrm->prev_flush_failed;
+
+				gud_retry_failed_flush(gdrm, fb, &damage);
+				if (!prev_flush_failed)
+					dev_err_ratelimited(fb->dev->dev,
+							    "Failed to flush framebuffer: error=%d\n", ret);
+			}
+			break;
+		}
+
+		gdrm->prev_flush_failed = false;
+	}
+
+	drm_framebuffer_put(fb);
+out:
+	drm_dev_exit(idx);
+}
+
+static void gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
+				struct drm_rect *damage)
+{
+	struct drm_framebuffer *old_fb = NULL;
+
+	mutex_lock(&gdrm->damage_lock);
+
+	if (fb != gdrm->fb) {
+		old_fb = gdrm->fb;
+		drm_framebuffer_get(fb);
+		gdrm->fb = fb;
+	}
+
+	gud_add_damage(gdrm, damage);
+
+	mutex_unlock(&gdrm->damage_lock);
+
+	queue_work(system_long_wq, &gdrm->work);
+
+	if (old_fb)
+		drm_framebuffer_put(old_fb);
+}
+
+int gud_pipe_check(struct drm_simple_display_pipe *pipe,
+		   struct drm_plane_state *new_plane_state,
+		   struct drm_crtc_state *new_crtc_state)
+{
+	struct gud_device *gdrm = to_gud_device(pipe->crtc.dev);
+	struct drm_plane_state *old_plane_state = pipe->plane.state;
+	const struct drm_display_mode *mode = &new_crtc_state->mode;
+	struct drm_atomic_state *state = new_plane_state->state;
+	struct drm_framebuffer *old_fb = old_plane_state->fb;
+	struct drm_connector_state *connector_state = NULL;
+	struct drm_framebuffer *fb = new_plane_state->fb;
+	const struct drm_format_info *format = fb->format;
+	struct drm_connector *connector;
+	unsigned int i, num_properties;
+	struct gud_state_req *req;
+	int idx, ret;
+	size_t len;
+
+	if (WARN_ON_ONCE(!fb))
+		return -EINVAL;
+
+	if (old_plane_state->rotation != new_plane_state->rotation)
+		new_crtc_state->mode_changed = true;
+
+	if (old_fb && old_fb->format != format)
+		new_crtc_state->mode_changed = true;
+
+	if (!new_crtc_state->mode_changed && !new_crtc_state->connectors_changed)
+		return 0;
+
+	/* Only one connector is supported */
+	if (hweight32(new_crtc_state->connector_mask) != 1)
+		return -EINVAL;
+
+	if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
+		format = gdrm->xrgb8888_emulation_format;
+
+	for_each_new_connector_in_state(state, connector, connector_state, i) {
+		if (connector_state->crtc)
+			break;
+	}
+
+	/*
+	 * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
+	 * the connector included in the state.
+	 */
+	if (!connector_state) {
+		struct drm_connector_list_iter conn_iter;
+
+		drm_connector_list_iter_begin(pipe->crtc.dev, &conn_iter);
+		drm_for_each_connector_iter(connector, &conn_iter) {
+			if (connector->state->crtc) {
+				connector_state = connector->state;
+				break;
+			}
+		}
+		drm_connector_list_iter_end(&conn_iter);
+	}
+
+	if (WARN_ON_ONCE(!connector_state))
+		return -ENOENT;
+
+	len = struct_size(req, properties,
+			  GUD_PROPERTIES_MAX_NUM + GUD_CONNECTOR_PROPERTIES_MAX_NUM);
+	req = kzalloc(len, GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	gud_from_display_mode(&req->mode, mode);
+
+	req->format = gud_from_fourcc(format->format);
+	if (WARN_ON_ONCE(!req->format)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	req->connector = drm_connector_index(connector_state->connector);
+
+	ret = gud_connector_fill_properties(connector_state, req->properties);
+	if (ret < 0)
+		goto out;
+
+	num_properties = ret;
+	for (i = 0; i < gdrm->num_properties; i++) {
+		u16 prop = gdrm->properties[i];
+		u64 val;
+
+		switch (prop) {
+		case GUD_PROPERTY_ROTATION:
+			/* DRM UAPI matches the protocol so use value directly */
+			val = new_plane_state->rotation;
+			break;
+		default:
+			WARN_ON_ONCE(1);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		req->properties[num_properties + i].prop = cpu_to_le16(prop);
+		req->properties[num_properties + i].val = cpu_to_le64(val);
+		num_properties++;
+	}
+
+	if (drm_dev_enter(fb->dev, &idx)) {
+		len = struct_size(req, properties, num_properties);
+		ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
+		drm_dev_exit(idx);
+	}  else {
+		ret = -ENODEV;
+	}
+out:
+	kfree(req);
+
+	return ret;
+}
+
+void gud_pipe_update(struct drm_simple_display_pipe *pipe,
+		     struct drm_plane_state *old_state)
+{
+	struct drm_device *drm = pipe->crtc.dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	struct drm_plane_state *state = pipe->plane.state;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_rect damage;
+	int idx;
+
+	if (crtc->state->mode_changed || !crtc->state->enable) {
+		cancel_work_sync(&gdrm->work);
+		mutex_lock(&gdrm->damage_lock);
+		if (gdrm->fb) {
+			drm_framebuffer_put(gdrm->fb);
+			gdrm->fb = NULL;
+		}
+		gud_clear_damage(gdrm);
+		mutex_unlock(&gdrm->damage_lock);
+	}
+
+	if (!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 (drm_atomic_helper_damage_merged(old_state, state, &damage)) {
+		if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
+			drm_rect_init(&damage, 0, 0, fb->width, fb->height);
+		gud_fb_queue_damage(gdrm, fb, &damage);
+	}
+
+	if (!crtc->state->enable)
+		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
+
+	drm_dev_exit(idx);
+}