drivers/gpu/drm/gud/gud_pipe.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2020 Noralf Trønnes
   4  */
   5
   6 #include <linux/lz4.h>
   7 #include <linux/usb.h>
   8 #include <linux/vmalloc.h>
   9 #include <linux/workqueue.h>
  10
  11 #include <drm/drm_atomic.h>
  12 #include <drm/drm_connector.h>
  13 #include <drm/drm_damage_helper.h>
  14 #include <drm/drm_drv.h>
  15 #include <drm/drm_format_helper.h>
  16 #include <drm/drm_fourcc.h>
  17 #include <drm/drm_framebuffer.h>
  18 #include <drm/drm_gem.h>
  19 #include <drm/drm_gem_atomic_helper.h>
  20 #include <drm/drm_gem_framebuffer_helper.h>
  21 #include <drm/drm_print.h>
  22 #include <drm/drm_rect.h>
  23 #include <drm/drm_simple_kms_helper.h>
  24 #include <drm/gud.h>
  25
  26 #include "gud_internal.h"
  27
  28 /*
  29  * Some userspace rendering loops run all displays in the same loop.
  30  * This means that a fast display will have to wait for a slow one.
  31  * Such users might want to enable this module parameter.
  32  */
  33 static bool gud_async_flush;
  34 module_param_named(async_flush, gud_async_flush, bool, 0644);
  35 MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=0]");
  36
  37 /*
  38  * FIXME: The driver is probably broken on Big Endian machines.
  39  * See discussion:
  40  * https://lore.kernel.org/dri-devel/CAKb7UvihLX0hgBOP3VBG7O+atwZcUVCPVuBdfmDMpg0NjXe-cQ@mail.gmail.com/
  41  */
  42
  43 static bool gud_is_big_endian(void)
  44 {
  45 #if defined(__BIG_ENDIAN)
  46         return true;
  47 #else
  48         return false;
  49 #endif
  50 }
  51
  52 static size_t gud_xrgb8888_to_r124(u8 *dst, const struct drm_format_info *format,
  53                                    void *src, struct drm_framebuffer *fb,
  54                                    struct drm_rect *rect)
  55 {
  56         unsigned int block_width = drm_format_info_block_width(format, 0);
  57         unsigned int bits_per_pixel = 8 / block_width;
  58         unsigned int x, y, width, height;
  59         u8 pix, *pix8, *block = dst; /* Assign to silence compiler warning */
  60         struct iosys_map dst_map, vmap;
  61         size_t len;
  62         void *buf;
  63
  64         WARN_ON_ONCE(format->char_per_block[0] != 1);
  65
  66         /* Start on a byte boundary */
  67         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
  68         width = drm_rect_width(rect);
  69         height = drm_rect_height(rect);
  70         len = drm_format_info_min_pitch(format, 0, width) * height;
  71
  72         buf = kmalloc(width * height, GFP_KERNEL);
  73         if (!buf)
  74                 return 0;
  75
  76         iosys_map_set_vaddr(&dst_map, buf);
  77         iosys_map_set_vaddr(&vmap, src);
  78         drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, rect);
  79         pix8 = buf;
  80
  81         for (y = 0; y < height; y++) {
  82                 for (x = 0; x < width; x++) {
  83                         unsigned int pixpos = x % block_width; /* within byte from the left */
  84                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
  85
  86                         if (!pixpos) {
  87                                 block = dst++;
  88                                 *block = 0;
  89                         }
  90
  91                         pix = (*pix8++) >> (8 - bits_per_pixel);
  92                         *block |= pix << pixshift;
  93                 }
  94         }
  95
  96         kfree(buf);
  97
  98         return len;
  99 }
 100
 101 static size_t gud_xrgb8888_to_color(u8 *dst, const struct drm_format_info *format,
 102                                     void *src, struct drm_framebuffer *fb,
 103                                     struct drm_rect *rect)
 104 {
 105         unsigned int block_width = drm_format_info_block_width(format, 0);
 106         unsigned int bits_per_pixel = 8 / block_width;
 107         u8 r, g, b, pix, *block = dst; /* Assign to silence compiler warning */
 108         unsigned int x, y, width;
 109         __le32 *sbuf32;
 110         u32 pix32;
 111         size_t len;
 112
 113         /* Start on a byte boundary */
 114         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
 115         width = drm_rect_width(rect);
 116         len = drm_format_info_min_pitch(format, 0, width) * drm_rect_height(rect);
 117
 118         for (y = rect->y1; y < rect->y2; y++) {
 119                 sbuf32 = src + (y * fb->pitches[0]);
 120                 sbuf32 += rect->x1;
 121
 122                 for (x = 0; x < width; x++) {
 123                         unsigned int pixpos = x % block_width; /* within byte from the left */
 124                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
 125
 126                         if (!pixpos) {
 127                                 block = dst++;
 128                                 *block = 0;
 129                         }
 130
 131                         pix32 = le32_to_cpu(*sbuf32++);
 132                         r = pix32 >> 16;
 133                         g = pix32 >> 8;
 134                         b = pix32;
 135
 136                         switch (format->format) {
 137                         case GUD_DRM_FORMAT_XRGB1111:
 138                                 pix = ((r >> 7) << 2) | ((g >> 7) << 1) | (b >> 7);
 139                                 break;
 140                         default:
 141                                 WARN_ON_ONCE(1);
 142                                 return len;
 143                         }
 144
 145                         *block |= pix << pixshift;
 146                 }
 147         }
 148
 149         return len;
 150 }
 151
 152 static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
 153                           const struct iosys_map *src, bool cached_reads,
 154                           const struct drm_format_info *format, struct drm_rect *rect,
 155                           struct gud_set_buffer_req *req)
 156 {
 157         u8 compression = gdrm->compression;
 158         struct iosys_map dst;
 159         void *vaddr, *buf;
 160         size_t pitch, len;
 161
 162         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(rect));
 163         len = pitch * drm_rect_height(rect);
 164         if (len > gdrm->bulk_len)
 165                 return -E2BIG;
 166
 167         vaddr = src[0].vaddr;
 168 retry:
 169         if (compression)
 170                 buf = gdrm->compress_buf;
 171         else
 172                 buf = gdrm->bulk_buf;
 173         iosys_map_set_vaddr(&dst, buf);
 174
 175         /*
 176          * Imported buffers are assumed to be write-combined and thus uncached
 177          * with slow reads (at least on ARM).
 178          */
 179         if (format != fb->format) {
 180                 if (format->format == GUD_DRM_FORMAT_R1) {
 181                         len = gud_xrgb8888_to_r124(buf, format, vaddr, fb, rect);
 182                         if (!len)
 183                                 return -ENOMEM;
 184                 } else if (format->format == DRM_FORMAT_R8) {
 185                         drm_fb_xrgb8888_to_gray8(&dst, NULL, src, fb, rect);
 186                 } else if (format->format == DRM_FORMAT_RGB332) {
 187                         drm_fb_xrgb8888_to_rgb332(&dst, NULL, src, fb, rect);
 188                 } else if (format->format == DRM_FORMAT_RGB565) {
 189                         drm_fb_xrgb8888_to_rgb565(&dst, NULL, src, fb, rect,
 190                                                   gud_is_big_endian());
 191                 } else if (format->format == DRM_FORMAT_RGB888) {
 192                         drm_fb_xrgb8888_to_rgb888(&dst, NULL, src, fb, rect);
 193                 } else {
 194                         len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
 195                 }
 196         } else if (gud_is_big_endian() && format->cpp[0] > 1) {
 197                 drm_fb_swab(&dst, NULL, src, fb, rect, cached_reads);
 198         } else if (compression && cached_reads && pitch == fb->pitches[0]) {
 199                 /* can compress directly from the framebuffer */
 200                 buf = vaddr + rect->y1 * pitch;
 201         } else {
 202                 drm_fb_memcpy(&dst, NULL, src, fb, rect);
 203         }
 204
 205         memset(req, 0, sizeof(*req));
 206         req->x = cpu_to_le32(rect->x1);
 207         req->y = cpu_to_le32(rect->y1);
 208         req->width = cpu_to_le32(drm_rect_width(rect));
 209         req->height = cpu_to_le32(drm_rect_height(rect));
 210         req->length = cpu_to_le32(len);
 211
 212         if (compression & GUD_COMPRESSION_LZ4) {
 213                 int complen;
 214
 215                 complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
 216                 if (complen <= 0) {
 217                         compression = 0;
 218                         goto retry;
 219                 }
 220
 221                 req->compression = GUD_COMPRESSION_LZ4;
 222                 req->compressed_length = cpu_to_le32(complen);
 223         }
 224
 225         return 0;
 226 }
 227
 228 struct gud_usb_bulk_context {
 229         struct timer_list timer;
 230         struct usb_sg_request sgr;
 231 };
 232
 233 static void gud_usb_bulk_timeout(struct timer_list *t)
 234 {
 235         struct gud_usb_bulk_context *ctx = from_timer(ctx, t, timer);
 236
 237         usb_sg_cancel(&ctx->sgr);
 238 }
 239
 240 static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
 241 {
 242         struct gud_usb_bulk_context ctx;
 243         int ret;
 244
 245         ret = usb_sg_init(&ctx.sgr, gud_to_usb_device(gdrm), gdrm->bulk_pipe, 0,
 246                           gdrm->bulk_sgt.sgl, gdrm->bulk_sgt.nents, len, GFP_KERNEL);
 247         if (ret)
 248                 return ret;
 249
 250         timer_setup_on_stack(&ctx.timer, gud_usb_bulk_timeout, 0);
 251         mod_timer(&ctx.timer, jiffies + msecs_to_jiffies(3000));
 252
 253         usb_sg_wait(&ctx.sgr);
 254
 255         if (!del_timer_sync(&ctx.timer))
 256                 ret = -ETIMEDOUT;
 257         else if (ctx.sgr.status < 0)
 258                 ret = ctx.sgr.status;
 259         else if (ctx.sgr.bytes != len)
 260                 ret = -EIO;
 261
 262         destroy_timer_on_stack(&ctx.timer);
 263
 264         return ret;
 265 }
 266
 267 static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
 268                           const struct iosys_map *src, bool cached_reads,
 269                           const struct drm_format_info *format, struct drm_rect *rect)
 270 {
 271         struct gud_set_buffer_req req;
 272         size_t len, trlen;
 273         int ret;
 274
 275         drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 276
 277         ret = gud_prep_flush(gdrm, fb, src, cached_reads, format, rect, &req);
 278         if (ret)
 279                 return ret;
 280
 281         len = le32_to_cpu(req.length);
 282
 283         if (req.compression)
 284                 trlen = le32_to_cpu(req.compressed_length);
 285         else
 286                 trlen = len;
 287
 288         gdrm->stats_length += len;
 289         /* Did it wrap around? */
 290         if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
 291                 gdrm->stats_length = len;
 292                 gdrm->stats_actual_length = 0;
 293         }
 294         gdrm->stats_actual_length += trlen;
 295
 296         if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
 297                 ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
 298                 if (ret)
 299                         return ret;
 300         }
 301
 302         ret = gud_usb_bulk(gdrm, trlen);
 303         if (ret)
 304                 gdrm->stats_num_errors++;
 305
 306         return ret;
 307 }
 308
 309 void gud_clear_damage(struct gud_device *gdrm)
 310 {
 311         gdrm->damage.x1 = INT_MAX;
 312         gdrm->damage.y1 = INT_MAX;
 313         gdrm->damage.x2 = 0;
 314         gdrm->damage.y2 = 0;
 315 }
 316
 317 static void gud_flush_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 318                              const struct iosys_map *src, bool cached_reads,
 319                              struct drm_rect *damage)
 320 {
 321         const struct drm_format_info *format;
 322         unsigned int i, lines;
 323         size_t pitch;
 324         int ret;
 325
 326         format = fb->format;
 327         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 328                 format = gdrm->xrgb8888_emulation_format;
 329
 330         /* Split update if it's too big */
 331         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(damage));
 332         lines = drm_rect_height(damage);
 333
 334         if (gdrm->bulk_len < lines * pitch)
 335                 lines = gdrm->bulk_len / pitch;
 336
 337         for (i = 0; i < DIV_ROUND_UP(drm_rect_height(damage), lines); i++) {
 338                 struct drm_rect rect = *damage;
 339
 340                 rect.y1 += i * lines;
 341                 rect.y2 = min_t(u32, rect.y1 + lines, damage->y2);
 342
 343                 ret = gud_flush_rect(gdrm, fb, src, cached_reads, format, &rect);
 344                 if (ret) {
 345                         if (ret != -ENODEV && ret != -ECONNRESET &&
 346                             ret != -ESHUTDOWN && ret != -EPROTO)
 347                                 dev_err_ratelimited(fb->dev->dev,
 348                                                     "Failed to flush framebuffer: error=%d\n", ret);
 349                         gdrm->prev_flush_failed = true;
 350                         break;
 351                 }
 352         }
 353 }
 354
 355 void gud_flush_work(struct work_struct *work)
 356 {
 357         struct gud_device *gdrm = container_of(work, struct gud_device, work);
 358         struct iosys_map shadow_map;
 359         struct drm_framebuffer *fb;
 360         struct drm_rect damage;
 361         int idx;
 362
 363         if (!drm_dev_enter(&gdrm->drm, &idx))
 364                 return;
 365
 366         mutex_lock(&gdrm->damage_lock);
 367         fb = gdrm->fb;
 368         gdrm->fb = NULL;
 369         iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
 370         damage = gdrm->damage;
 371         gud_clear_damage(gdrm);
 372         mutex_unlock(&gdrm->damage_lock);
 373
 374         if (!fb)
 375                 goto out;
 376
 377         gud_flush_damage(gdrm, fb, &shadow_map, true, &damage);
 378
 379         drm_framebuffer_put(fb);
 380 out:
 381         drm_dev_exit(idx);
 382 }
 383
 384 static int gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 385                                const struct iosys_map *src, struct drm_rect *damage)
 386 {
 387         struct drm_framebuffer *old_fb = NULL;
 388         struct iosys_map shadow_map;
 389
 390         mutex_lock(&gdrm->damage_lock);
 391
 392         if (!gdrm->shadow_buf) {
 393                 gdrm->shadow_buf = vcalloc(fb->pitches[0], fb->height);
 394                 if (!gdrm->shadow_buf) {
 395                         mutex_unlock(&gdrm->damage_lock);
 396                         return -ENOMEM;
 397                 }
 398         }
 399
 400         iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
 401         iosys_map_incr(&shadow_map, drm_fb_clip_offset(fb->pitches[0], fb->format, damage));
 402         drm_fb_memcpy(&shadow_map, fb->pitches, src, fb, damage);
 403
 404         if (fb != gdrm->fb) {
 405                 old_fb = gdrm->fb;
 406                 drm_framebuffer_get(fb);
 407                 gdrm->fb = fb;
 408         }
 409
 410         gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
 411         gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
 412         gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
 413         gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
 414
 415         mutex_unlock(&gdrm->damage_lock);
 416
 417         queue_work(system_long_wq, &gdrm->work);
 418
 419         if (old_fb)
 420                 drm_framebuffer_put(old_fb);
 421
 422         return 0;
 423 }
 424
 425 static void gud_fb_handle_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 426                                  const struct iosys_map *src, struct drm_rect *damage)
 427 {
 428         int ret;
 429
 430         if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
 431                 drm_rect_init(damage, 0, 0, fb->width, fb->height);
 432
 433         if (gud_async_flush) {
 434                 ret = gud_fb_queue_damage(gdrm, fb, src, damage);
 435                 if (ret != -ENOMEM)
 436                         return;
 437         }
 438
 439         /* Imported buffers are assumed to be WriteCombined with uncached reads */
 440         gud_flush_damage(gdrm, fb, src, !fb->obj[0]->import_attach, damage);
 441 }
 442
 443 int gud_pipe_check(struct drm_simple_display_pipe *pipe,
 444                    struct drm_plane_state *new_plane_state,
 445                    struct drm_crtc_state *new_crtc_state)
 446 {
 447         struct gud_device *gdrm = to_gud_device(pipe->crtc.dev);
 448         struct drm_plane_state *old_plane_state = pipe->plane.state;
 449         const struct drm_display_mode *mode = &new_crtc_state->mode;
 450         struct drm_atomic_state *state = new_plane_state->state;
 451         struct drm_framebuffer *old_fb = old_plane_state->fb;
 452         struct drm_connector_state *connector_state = NULL;
 453         struct drm_framebuffer *fb = new_plane_state->fb;
 454         const struct drm_format_info *format = fb->format;
 455         struct drm_connector *connector;
 456         unsigned int i, num_properties;
 457         struct gud_state_req *req;
 458         int idx, ret;
 459         size_t len;
 460
 461         if (WARN_ON_ONCE(!fb))
 462                 return -EINVAL;
 463
 464         if (old_plane_state->rotation != new_plane_state->rotation)
 465                 new_crtc_state->mode_changed = true;
 466
 467         if (old_fb && old_fb->format != format)
 468                 new_crtc_state->mode_changed = true;
 469
 470         if (!new_crtc_state->mode_changed && !new_crtc_state->connectors_changed)
 471                 return 0;
 472
 473         /* Only one connector is supported */
 474         if (hweight32(new_crtc_state->connector_mask) != 1)
 475                 return -EINVAL;
 476
 477         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 478                 format = gdrm->xrgb8888_emulation_format;
 479
 480         for_each_new_connector_in_state(state, connector, connector_state, i) {
 481                 if (connector_state->crtc)
 482                         break;
 483         }
 484
 485         /*
 486          * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
 487          * the connector included in the state.
 488          */
 489         if (!connector_state) {
 490                 struct drm_connector_list_iter conn_iter;
 491
 492                 drm_connector_list_iter_begin(pipe->crtc.dev, &conn_iter);
 493                 drm_for_each_connector_iter(connector, &conn_iter) {
 494                         if (connector->state->crtc) {
 495                                 connector_state = connector->state;
 496                                 break;
 497                         }
 498                 }
 499                 drm_connector_list_iter_end(&conn_iter);
 500         }
 501
 502         if (WARN_ON_ONCE(!connector_state))
 503                 return -ENOENT;
 504
 505         len = struct_size(req, properties,
 506                           size_add(GUD_PROPERTIES_MAX_NUM, GUD_CONNECTOR_PROPERTIES_MAX_NUM));
 507         req = kzalloc(len, GFP_KERNEL);
 508         if (!req)
 509                 return -ENOMEM;
 510
 511         gud_from_display_mode(&req->mode, mode);
 512
 513         req->format = gud_from_fourcc(format->format);
 514         if (WARN_ON_ONCE(!req->format)) {
 515                 ret = -EINVAL;
 516                 goto out;
 517         }
 518
 519         req->connector = drm_connector_index(connector_state->connector);
 520
 521         ret = gud_connector_fill_properties(connector_state, req->properties);
 522         if (ret < 0)
 523                 goto out;
 524
 525         num_properties = ret;
 526         for (i = 0; i < gdrm->num_properties; i++) {
 527                 u16 prop = gdrm->properties[i];
 528                 u64 val;
 529
 530                 switch (prop) {
 531                 case GUD_PROPERTY_ROTATION:
 532                         /* DRM UAPI matches the protocol so use value directly */
 533                         val = new_plane_state->rotation;
 534                         break;
 535                 default:
 536                         WARN_ON_ONCE(1);
 537                         ret = -EINVAL;
 538                         goto out;
 539                 }
 540
 541                 req->properties[num_properties + i].prop = cpu_to_le16(prop);
 542                 req->properties[num_properties + i].val = cpu_to_le64(val);
 543                 num_properties++;
 544         }
 545
 546         if (drm_dev_enter(fb->dev, &idx)) {
 547                 len = struct_size(req, properties, num_properties);
 548                 ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
 549                 drm_dev_exit(idx);
 550         }  else {
 551                 ret = -ENODEV;
 552         }
 553 out:
 554         kfree(req);
 555
 556         return ret;
 557 }
 558
 559 void gud_pipe_update(struct drm_simple_display_pipe *pipe,
 560                      struct drm_plane_state *old_state)
 561 {
 562         struct drm_device *drm = pipe->crtc.dev;
 563         struct gud_device *gdrm = to_gud_device(drm);
 564         struct drm_plane_state *state = pipe->plane.state;
 565         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 566         struct drm_framebuffer *fb = state->fb;
 567         struct drm_crtc *crtc = &pipe->crtc;
 568         struct drm_rect damage;
 569         int ret, idx;
 570
 571         if (crtc->state->mode_changed || !crtc->state->enable) {
 572                 cancel_work_sync(&gdrm->work);
 573                 mutex_lock(&gdrm->damage_lock);
 574                 if (gdrm->fb) {
 575                         drm_framebuffer_put(gdrm->fb);
 576                         gdrm->fb = NULL;
 577                 }
 578                 gud_clear_damage(gdrm);
 579                 vfree(gdrm->shadow_buf);
 580                 gdrm->shadow_buf = NULL;
 581                 mutex_unlock(&gdrm->damage_lock);
 582         }
 583
 584         if (!drm_dev_enter(drm, &idx))
 585                 return;
 586
 587         if (!old_state->fb)
 588                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
 589
 590         if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
 591                 gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
 592
 593         if (crtc->state->active_changed)
 594                 gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
 595
 596         if (!fb)
 597                 goto ctrl_disable;
 598
 599         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 600         if (ret)
 601                 goto ctrl_disable;
 602
 603         if (drm_atomic_helper_damage_merged(old_state, state, &damage))
 604                 gud_fb_handle_damage(gdrm, fb, &shadow_plane_state->data[0], &damage);
 605
 606         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 607
 608 ctrl_disable:
 609         if (!crtc->state->enable)
 610                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
 611
 612         drm_dev_exit(idx);
 613 }