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                                    struct drm_format_conv_state *fmtcnv_state)
  56 {
  57         unsigned int block_width = drm_format_info_block_width(format, 0);
  58         unsigned int bits_per_pixel = 8 / block_width;
  59         unsigned int x, y, width, height;
  60         u8 pix, *pix8, *block = dst; /* Assign to silence compiler warning */
  61         struct iosys_map dst_map, vmap;
  62         size_t len;
  63         void *buf;
  64
  65         WARN_ON_ONCE(format->char_per_block[0] != 1);
  66
  67         /* Start on a byte boundary */
  68         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
  69         width = drm_rect_width(rect);
  70         height = drm_rect_height(rect);
  71         len = drm_format_info_min_pitch(format, 0, width) * height;
  72
  73         buf = kmalloc(width * height, GFP_KERNEL);
  74         if (!buf)
  75                 return 0;
  76
  77         iosys_map_set_vaddr(&dst_map, buf);
  78         iosys_map_set_vaddr(&vmap, src);
  79         drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, rect, fmtcnv_state);
  80         pix8 = buf;
  81
  82         for (y = 0; y < height; y++) {
  83                 for (x = 0; x < width; x++) {
  84                         unsigned int pixpos = x % block_width; /* within byte from the left */
  85                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
  86
  87                         if (!pixpos) {
  88                                 block = dst++;
  89                                 *block = 0;
  90                         }
  91
  92                         pix = (*pix8++) >> (8 - bits_per_pixel);
  93                         *block |= pix << pixshift;
  94                 }
  95         }
  96
  97         kfree(buf);
  98
  99         return len;
 100 }
 101
 102 static size_t gud_xrgb8888_to_color(u8 *dst, const struct drm_format_info *format,
 103                                     void *src, struct drm_framebuffer *fb,
 104                                     struct drm_rect *rect)
 105 {
 106         unsigned int block_width = drm_format_info_block_width(format, 0);
 107         unsigned int bits_per_pixel = 8 / block_width;
 108         u8 r, g, b, pix, *block = dst; /* Assign to silence compiler warning */
 109         unsigned int x, y, width;
 110         __le32 *sbuf32;
 111         u32 pix32;
 112         size_t len;
 113
 114         /* Start on a byte boundary */
 115         rect->x1 = ALIGN_DOWN(rect->x1, block_width);
 116         width = drm_rect_width(rect);
 117         len = drm_format_info_min_pitch(format, 0, width) * drm_rect_height(rect);
 118
 119         for (y = rect->y1; y < rect->y2; y++) {
 120                 sbuf32 = src + (y * fb->pitches[0]);
 121                 sbuf32 += rect->x1;
 122
 123                 for (x = 0; x < width; x++) {
 124                         unsigned int pixpos = x % block_width; /* within byte from the left */
 125                         unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
 126
 127                         if (!pixpos) {
 128                                 block = dst++;
 129                                 *block = 0;
 130                         }
 131
 132                         pix32 = le32_to_cpu(*sbuf32++);
 133                         r = pix32 >> 16;
 134                         g = pix32 >> 8;
 135                         b = pix32;
 136
 137                         switch (format->format) {
 138                         case GUD_DRM_FORMAT_XRGB1111:
 139                                 pix = ((r >> 7) << 2) | ((g >> 7) << 1) | (b >> 7);
 140                                 break;
 141                         default:
 142                                 WARN_ON_ONCE(1);
 143                                 return len;
 144                         }
 145
 146                         *block |= pix << pixshift;
 147                 }
 148         }
 149
 150         return len;
 151 }
 152
 153 static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
 154                           const struct iosys_map *src, bool cached_reads,
 155                           const struct drm_format_info *format, struct drm_rect *rect,
 156                           struct gud_set_buffer_req *req,
 157                           struct drm_format_conv_state *fmtcnv_state)
 158 {
 159         u8 compression = gdrm->compression;
 160         struct iosys_map dst;
 161         void *vaddr, *buf;
 162         size_t pitch, len;
 163
 164         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(rect));
 165         len = pitch * drm_rect_height(rect);
 166         if (len > gdrm->bulk_len)
 167                 return -E2BIG;
 168
 169         vaddr = src[0].vaddr;
 170 retry:
 171         if (compression)
 172                 buf = gdrm->compress_buf;
 173         else
 174                 buf = gdrm->bulk_buf;
 175         iosys_map_set_vaddr(&dst, buf);
 176
 177         /*
 178          * Imported buffers are assumed to be write-combined and thus uncached
 179          * with slow reads (at least on ARM).
 180          */
 181         if (format != fb->format) {
 182                 if (format->format == GUD_DRM_FORMAT_R1) {
 183                         len = gud_xrgb8888_to_r124(buf, format, vaddr, fb, rect, fmtcnv_state);
 184                         if (!len)
 185                                 return -ENOMEM;
 186                 } else if (format->format == DRM_FORMAT_R8) {
 187                         drm_fb_xrgb8888_to_gray8(&dst, NULL, src, fb, rect, fmtcnv_state);
 188                 } else if (format->format == DRM_FORMAT_RGB332) {
 189                         drm_fb_xrgb8888_to_rgb332(&dst, NULL, src, fb, rect, fmtcnv_state);
 190                 } else if (format->format == DRM_FORMAT_RGB565) {
 191                         drm_fb_xrgb8888_to_rgb565(&dst, NULL, src, fb, rect, fmtcnv_state,
 192                                                   gud_is_big_endian());
 193                 } else if (format->format == DRM_FORMAT_RGB888) {
 194                         drm_fb_xrgb8888_to_rgb888(&dst, NULL, src, fb, rect, fmtcnv_state);
 195                 } else {
 196                         len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
 197                 }
 198         } else if (gud_is_big_endian() && format->cpp[0] > 1) {
 199                 drm_fb_swab(&dst, NULL, src, fb, rect, cached_reads, fmtcnv_state);
 200         } else if (compression && cached_reads && pitch == fb->pitches[0]) {
 201                 /* can compress directly from the framebuffer */
 202                 buf = vaddr + rect->y1 * pitch;
 203         } else {
 204                 drm_fb_memcpy(&dst, NULL, src, fb, rect);
 205         }
 206
 207         memset(req, 0, sizeof(*req));
 208         req->x = cpu_to_le32(rect->x1);
 209         req->y = cpu_to_le32(rect->y1);
 210         req->width = cpu_to_le32(drm_rect_width(rect));
 211         req->height = cpu_to_le32(drm_rect_height(rect));
 212         req->length = cpu_to_le32(len);
 213
 214         if (compression & GUD_COMPRESSION_LZ4) {
 215                 int complen;
 216
 217                 complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
 218                 if (complen <= 0) {
 219                         compression = 0;
 220                         goto retry;
 221                 }
 222
 223                 req->compression = GUD_COMPRESSION_LZ4;
 224                 req->compressed_length = cpu_to_le32(complen);
 225         }
 226
 227         return 0;
 228 }
 229
 230 struct gud_usb_bulk_context {
 231         struct timer_list timer;
 232         struct usb_sg_request sgr;
 233 };
 234
 235 static void gud_usb_bulk_timeout(struct timer_list *t)
 236 {
 237         struct gud_usb_bulk_context *ctx = from_timer(ctx, t, timer);
 238
 239         usb_sg_cancel(&ctx->sgr);
 240 }
 241
 242 static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
 243 {
 244         struct gud_usb_bulk_context ctx;
 245         int ret;
 246
 247         ret = usb_sg_init(&ctx.sgr, gud_to_usb_device(gdrm), gdrm->bulk_pipe, 0,
 248                           gdrm->bulk_sgt.sgl, gdrm->bulk_sgt.nents, len, GFP_KERNEL);
 249         if (ret)
 250                 return ret;
 251
 252         timer_setup_on_stack(&ctx.timer, gud_usb_bulk_timeout, 0);
 253         mod_timer(&ctx.timer, jiffies + msecs_to_jiffies(3000));
 254
 255         usb_sg_wait(&ctx.sgr);
 256
 257         if (!del_timer_sync(&ctx.timer))
 258                 ret = -ETIMEDOUT;
 259         else if (ctx.sgr.status < 0)
 260                 ret = ctx.sgr.status;
 261         else if (ctx.sgr.bytes != len)
 262                 ret = -EIO;
 263
 264         destroy_timer_on_stack(&ctx.timer);
 265
 266         return ret;
 267 }
 268
 269 static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
 270                           const struct iosys_map *src, bool cached_reads,
 271                           const struct drm_format_info *format, struct drm_rect *rect,
 272                           struct drm_format_conv_state *fmtcnv_state)
 273 {
 274         struct gud_set_buffer_req req;
 275         size_t len, trlen;
 276         int ret;
 277
 278         drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
 279
 280         ret = gud_prep_flush(gdrm, fb, src, cached_reads, format, rect, &req, fmtcnv_state);
 281         if (ret)
 282                 return ret;
 283
 284         len = le32_to_cpu(req.length);
 285
 286         if (req.compression)
 287                 trlen = le32_to_cpu(req.compressed_length);
 288         else
 289                 trlen = len;
 290
 291         gdrm->stats_length += len;
 292         /* Did it wrap around? */
 293         if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
 294                 gdrm->stats_length = len;
 295                 gdrm->stats_actual_length = 0;
 296         }
 297         gdrm->stats_actual_length += trlen;
 298
 299         if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
 300                 ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
 301                 if (ret)
 302                         return ret;
 303         }
 304
 305         ret = gud_usb_bulk(gdrm, trlen);
 306         if (ret)
 307                 gdrm->stats_num_errors++;
 308
 309         return ret;
 310 }
 311
 312 void gud_clear_damage(struct gud_device *gdrm)
 313 {
 314         gdrm->damage.x1 = INT_MAX;
 315         gdrm->damage.y1 = INT_MAX;
 316         gdrm->damage.x2 = 0;
 317         gdrm->damage.y2 = 0;
 318 }
 319
 320 static void gud_flush_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 321                              const struct iosys_map *src, bool cached_reads,
 322                              struct drm_rect *damage)
 323 {
 324         struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
 325         const struct drm_format_info *format;
 326         unsigned int i, lines;
 327         size_t pitch;
 328         int ret;
 329
 330         format = fb->format;
 331         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 332                 format = gdrm->xrgb8888_emulation_format;
 333
 334         /* Split update if it's too big */
 335         pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(damage));
 336         lines = drm_rect_height(damage);
 337
 338         if (gdrm->bulk_len < lines * pitch)
 339                 lines = gdrm->bulk_len / pitch;
 340
 341         for (i = 0; i < DIV_ROUND_UP(drm_rect_height(damage), lines); i++) {
 342                 struct drm_rect rect = *damage;
 343
 344                 rect.y1 += i * lines;
 345                 rect.y2 = min_t(u32, rect.y1 + lines, damage->y2);
 346
 347                 ret = gud_flush_rect(gdrm, fb, src, cached_reads, format, &rect, &fmtcnv_state);
 348                 if (ret) {
 349                         if (ret != -ENODEV && ret != -ECONNRESET &&
 350                             ret != -ESHUTDOWN && ret != -EPROTO)
 351                                 dev_err_ratelimited(fb->dev->dev,
 352                                                     "Failed to flush framebuffer: error=%d\n", ret);
 353                         gdrm->prev_flush_failed = true;
 354                         break;
 355                 }
 356         }
 357
 358         drm_format_conv_state_release(&fmtcnv_state);
 359 }
 360
 361 void gud_flush_work(struct work_struct *work)
 362 {
 363         struct gud_device *gdrm = container_of(work, struct gud_device, work);
 364         struct iosys_map shadow_map;
 365         struct drm_framebuffer *fb;
 366         struct drm_rect damage;
 367         int idx;
 368
 369         if (!drm_dev_enter(&gdrm->drm, &idx))
 370                 return;
 371
 372         mutex_lock(&gdrm->damage_lock);
 373         fb = gdrm->fb;
 374         gdrm->fb = NULL;
 375         iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
 376         damage = gdrm->damage;
 377         gud_clear_damage(gdrm);
 378         mutex_unlock(&gdrm->damage_lock);
 379
 380         if (!fb)
 381                 goto out;
 382
 383         gud_flush_damage(gdrm, fb, &shadow_map, true, &damage);
 384
 385         drm_framebuffer_put(fb);
 386 out:
 387         drm_dev_exit(idx);
 388 }
 389
 390 static int gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 391                                const struct iosys_map *src, struct drm_rect *damage)
 392 {
 393         struct drm_framebuffer *old_fb = NULL;
 394         struct iosys_map shadow_map;
 395
 396         mutex_lock(&gdrm->damage_lock);
 397
 398         if (!gdrm->shadow_buf) {
 399                 gdrm->shadow_buf = vcalloc(fb->pitches[0], fb->height);
 400                 if (!gdrm->shadow_buf) {
 401                         mutex_unlock(&gdrm->damage_lock);
 402                         return -ENOMEM;
 403                 }
 404         }
 405
 406         iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
 407         iosys_map_incr(&shadow_map, drm_fb_clip_offset(fb->pitches[0], fb->format, damage));
 408         drm_fb_memcpy(&shadow_map, fb->pitches, src, fb, damage);
 409
 410         if (fb != gdrm->fb) {
 411                 old_fb = gdrm->fb;
 412                 drm_framebuffer_get(fb);
 413                 gdrm->fb = fb;
 414         }
 415
 416         gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
 417         gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
 418         gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
 419         gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
 420
 421         mutex_unlock(&gdrm->damage_lock);
 422
 423         queue_work(system_long_wq, &gdrm->work);
 424
 425         if (old_fb)
 426                 drm_framebuffer_put(old_fb);
 427
 428         return 0;
 429 }
 430
 431 static void gud_fb_handle_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
 432                                  const struct iosys_map *src, struct drm_rect *damage)
 433 {
 434         int ret;
 435
 436         if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
 437                 drm_rect_init(damage, 0, 0, fb->width, fb->height);
 438
 439         if (gud_async_flush) {
 440                 ret = gud_fb_queue_damage(gdrm, fb, src, damage);
 441                 if (ret != -ENOMEM)
 442                         return;
 443         }
 444
 445         /* Imported buffers are assumed to be WriteCombined with uncached reads */
 446         gud_flush_damage(gdrm, fb, src, !fb->obj[0]->import_attach, damage);
 447 }
 448
 449 int gud_pipe_check(struct drm_simple_display_pipe *pipe,
 450                    struct drm_plane_state *new_plane_state,
 451                    struct drm_crtc_state *new_crtc_state)
 452 {
 453         struct gud_device *gdrm = to_gud_device(pipe->crtc.dev);
 454         struct drm_plane_state *old_plane_state = pipe->plane.state;
 455         const struct drm_display_mode *mode = &new_crtc_state->mode;
 456         struct drm_atomic_state *state = new_plane_state->state;
 457         struct drm_framebuffer *old_fb = old_plane_state->fb;
 458         struct drm_connector_state *connector_state = NULL;
 459         struct drm_framebuffer *fb = new_plane_state->fb;
 460         const struct drm_format_info *format = fb->format;
 461         struct drm_connector *connector;
 462         unsigned int i, num_properties;
 463         struct gud_state_req *req;
 464         int idx, ret;
 465         size_t len;
 466
 467         if (WARN_ON_ONCE(!fb))
 468                 return -EINVAL;
 469
 470         if (old_plane_state->rotation != new_plane_state->rotation)
 471                 new_crtc_state->mode_changed = true;
 472
 473         if (old_fb && old_fb->format != format)
 474                 new_crtc_state->mode_changed = true;
 475
 476         if (!new_crtc_state->mode_changed && !new_crtc_state->connectors_changed)
 477                 return 0;
 478
 479         /* Only one connector is supported */
 480         if (hweight32(new_crtc_state->connector_mask) != 1)
 481                 return -EINVAL;
 482
 483         if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
 484                 format = gdrm->xrgb8888_emulation_format;
 485
 486         for_each_new_connector_in_state(state, connector, connector_state, i) {
 487                 if (connector_state->crtc)
 488                         break;
 489         }
 490
 491         /*
 492          * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
 493          * the connector included in the state.
 494          */
 495         if (!connector_state) {
 496                 struct drm_connector_list_iter conn_iter;
 497
 498                 drm_connector_list_iter_begin(pipe->crtc.dev, &conn_iter);
 499                 drm_for_each_connector_iter(connector, &conn_iter) {
 500                         if (connector->state->crtc) {
 501                                 connector_state = connector->state;
 502                                 break;
 503                         }
 504                 }
 505                 drm_connector_list_iter_end(&conn_iter);
 506         }
 507
 508         if (WARN_ON_ONCE(!connector_state))
 509                 return -ENOENT;
 510
 511         len = struct_size(req, properties,
 512                           size_add(GUD_PROPERTIES_MAX_NUM, GUD_CONNECTOR_PROPERTIES_MAX_NUM));
 513         req = kzalloc(len, GFP_KERNEL);
 514         if (!req)
 515                 return -ENOMEM;
 516
 517         gud_from_display_mode(&req->mode, mode);
 518
 519         req->format = gud_from_fourcc(format->format);
 520         if (WARN_ON_ONCE(!req->format)) {
 521                 ret = -EINVAL;
 522                 goto out;
 523         }
 524
 525         req->connector = drm_connector_index(connector_state->connector);
 526
 527         ret = gud_connector_fill_properties(connector_state, req->properties);
 528         if (ret < 0)
 529                 goto out;
 530
 531         num_properties = ret;
 532         for (i = 0; i < gdrm->num_properties; i++) {
 533                 u16 prop = gdrm->properties[i];
 534                 u64 val;
 535
 536                 switch (prop) {
 537                 case GUD_PROPERTY_ROTATION:
 538                         /* DRM UAPI matches the protocol so use value directly */
 539                         val = new_plane_state->rotation;
 540                         break;
 541                 default:
 542                         WARN_ON_ONCE(1);
 543                         ret = -EINVAL;
 544                         goto out;
 545                 }
 546
 547                 req->properties[num_properties + i].prop = cpu_to_le16(prop);
 548                 req->properties[num_properties + i].val = cpu_to_le64(val);
 549                 num_properties++;
 550         }
 551
 552         if (drm_dev_enter(fb->dev, &idx)) {
 553                 len = struct_size(req, properties, num_properties);
 554                 ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
 555                 drm_dev_exit(idx);
 556         }  else {
 557                 ret = -ENODEV;
 558         }
 559 out:
 560         kfree(req);
 561
 562         return ret;
 563 }
 564
 565 void gud_pipe_update(struct drm_simple_display_pipe *pipe,
 566                      struct drm_plane_state *old_state)
 567 {
 568         struct drm_device *drm = pipe->crtc.dev;
 569         struct gud_device *gdrm = to_gud_device(drm);
 570         struct drm_plane_state *state = pipe->plane.state;
 571         struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 572         struct drm_framebuffer *fb = state->fb;
 573         struct drm_crtc *crtc = &pipe->crtc;
 574         struct drm_rect damage;
 575         int ret, idx;
 576
 577         if (crtc->state->mode_changed || !crtc->state->enable) {
 578                 cancel_work_sync(&gdrm->work);
 579                 mutex_lock(&gdrm->damage_lock);
 580                 if (gdrm->fb) {
 581                         drm_framebuffer_put(gdrm->fb);
 582                         gdrm->fb = NULL;
 583                 }
 584                 gud_clear_damage(gdrm);
 585                 vfree(gdrm->shadow_buf);
 586                 gdrm->shadow_buf = NULL;
 587                 mutex_unlock(&gdrm->damage_lock);
 588         }
 589
 590         if (!drm_dev_enter(drm, &idx))
 591                 return;
 592
 593         if (!old_state->fb)
 594                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
 595
 596         if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))
 597                 gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
 598
 599         if (crtc->state->active_changed)
 600                 gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, crtc->state->active);
 601
 602         if (!fb)
 603                 goto ctrl_disable;
 604
 605         ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 606         if (ret)
 607                 goto ctrl_disable;
 608
 609         if (drm_atomic_helper_damage_merged(old_state, state, &damage))
 610                 gud_fb_handle_damage(gdrm, fb, &shadow_plane_state->data[0], &damage);
 611
 612         drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 613
 614 ctrl_disable:
 615         if (!crtc->state->enable)
 616                 gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
 617
 618         drm_dev_exit(idx);
 619 }