1 // SPDX-License-Identifier: GPL-2.0+
2
3 #include <linux/crc32.h>
4
5 #include <drm/drm_atomic.h>
6 #include <drm/drm_atomic_helper.h>
7 #include <drm/drm_blend.h>
8 #include <drm/drm_fourcc.h>
9 #include <drm/drm_fixed.h>
10 #include <drm/drm_gem_framebuffer_helper.h>
11 #include <drm/drm_vblank.h>
12 #include <linux/minmax.h>
13
14 #include "vkms_drv.h"
15
pre_mul_blend_channel(u16 src,u16 dst,u16 alpha)16 static u16 pre_mul_blend_channel(u16 src, u16 dst, u16 alpha)
17 {
18 u32 new_color;
19
20 new_color = (src * 0xffff + dst * (0xffff - alpha));
21
22 return DIV_ROUND_CLOSEST(new_color, 0xffff);
23 }
24
25 /**
26 * pre_mul_alpha_blend - alpha blending equation
27 * @stage_buffer: The line with the pixels from src_plane
28 * @output_buffer: A line buffer that receives all the blends output
29 * @x_start: The start offset
30 * @pixel_count: The number of pixels to blend
31 *
32 * The pixels [@x_start;@x_start+@pixel_count) in stage_buffer are blended at
33 * [@x_start;@x_start+@pixel_count) in output_buffer.
34 *
35 * The current DRM assumption is that pixel color values have been already
36 * pre-multiplied with the alpha channel values. See more
37 * drm_plane_create_blend_mode_property(). Also, this formula assumes a
38 * completely opaque background.
39 */
pre_mul_alpha_blend(const struct line_buffer * stage_buffer,struct line_buffer * output_buffer,int x_start,int pixel_count)40 static void pre_mul_alpha_blend(const struct line_buffer *stage_buffer,
41 struct line_buffer *output_buffer, int x_start, int pixel_count)
42 {
43 struct pixel_argb_u16 *out = &output_buffer->pixels[x_start];
44 const struct pixel_argb_u16 *in = &stage_buffer->pixels[x_start];
45
46 for (int i = 0; i < pixel_count; i++) {
47 out[i].a = (u16)0xffff;
48 out[i].r = pre_mul_blend_channel(in[i].r, out[i].r, in[i].a);
49 out[i].g = pre_mul_blend_channel(in[i].g, out[i].g, in[i].a);
50 out[i].b = pre_mul_blend_channel(in[i].b, out[i].b, in[i].a);
51 }
52 }
53
54
fill_background(const struct pixel_argb_u16 * background_color,struct line_buffer * output_buffer)55 static void fill_background(const struct pixel_argb_u16 *background_color,
56 struct line_buffer *output_buffer)
57 {
58 for (size_t i = 0; i < output_buffer->n_pixels; i++)
59 output_buffer->pixels[i] = *background_color;
60 }
61
62 // lerp(a, b, t) = a + (b - a) * t
lerp_u16(u16 a,u16 b,s64 t)63 static u16 lerp_u16(u16 a, u16 b, s64 t)
64 {
65 s64 a_fp = drm_int2fixp(a);
66 s64 b_fp = drm_int2fixp(b);
67
68 s64 delta = drm_fixp_mul(b_fp - a_fp, t);
69
70 return drm_fixp2int_round(a_fp + delta);
71 }
72
get_lut_index(const struct vkms_color_lut * lut,u16 channel_value)73 static s64 get_lut_index(const struct vkms_color_lut *lut, u16 channel_value)
74 {
75 s64 color_channel_fp = drm_int2fixp(channel_value);
76
77 return drm_fixp_mul(color_channel_fp, lut->channel_value2index_ratio);
78 }
79
80 /*
81 * This enum is related to the positions of the variables inside
82 * `struct drm_color_lut`, so the order of both needs to be the same.
83 */
84 enum lut_channel {
85 LUT_RED = 0,
86 LUT_GREEN,
87 LUT_BLUE,
88 LUT_RESERVED
89 };
90
apply_lut_to_channel_value(const struct vkms_color_lut * lut,u16 channel_value,enum lut_channel channel)91 static u16 apply_lut_to_channel_value(const struct vkms_color_lut *lut, u16 channel_value,
92 enum lut_channel channel)
93 {
94 s64 lut_index = get_lut_index(lut, channel_value);
95 u16 *floor_lut_value, *ceil_lut_value;
96 u16 floor_channel_value, ceil_channel_value;
97
98 /*
99 * This checks if `struct drm_color_lut` has any gap added by the compiler
100 * between the struct fields.
101 */
102 static_assert(sizeof(struct drm_color_lut) == sizeof(__u16) * 4);
103
104 floor_lut_value = (__u16 *)&lut->base[drm_fixp2int(lut_index)];
105 if (drm_fixp2int(lut_index) == (lut->lut_length - 1))
106 /* We're at the end of the LUT array, use same value for ceil and floor */
107 ceil_lut_value = floor_lut_value;
108 else
109 ceil_lut_value = (__u16 *)&lut->base[drm_fixp2int_ceil(lut_index)];
110
111 floor_channel_value = floor_lut_value[channel];
112 ceil_channel_value = ceil_lut_value[channel];
113
114 return lerp_u16(floor_channel_value, ceil_channel_value,
115 lut_index & DRM_FIXED_DECIMAL_MASK);
116 }
117
apply_lut(const struct vkms_crtc_state * crtc_state,struct line_buffer * output_buffer)118 static void apply_lut(const struct vkms_crtc_state *crtc_state, struct line_buffer *output_buffer)
119 {
120 if (!crtc_state->gamma_lut.base)
121 return;
122
123 if (!crtc_state->gamma_lut.lut_length)
124 return;
125
126 for (size_t x = 0; x < output_buffer->n_pixels; x++) {
127 struct pixel_argb_u16 *pixel = &output_buffer->pixels[x];
128
129 pixel->r = apply_lut_to_channel_value(&crtc_state->gamma_lut, pixel->r, LUT_RED);
130 pixel->g = apply_lut_to_channel_value(&crtc_state->gamma_lut, pixel->g, LUT_GREEN);
131 pixel->b = apply_lut_to_channel_value(&crtc_state->gamma_lut, pixel->b, LUT_BLUE);
132 }
133 }
134
135 /**
136 * direction_for_rotation() - Get the correct reading direction for a given rotation
137 *
138 * @rotation: Rotation to analyze. It correspond the field @frame_info.rotation.
139 *
140 * This function will use the @rotation setting of a source plane to compute the reading
141 * direction in this plane which correspond to a "left to right writing" in the CRTC.
142 * For example, if the buffer is reflected on X axis, the pixel must be read from right to left
143 * to be written from left to right on the CRTC.
144 */
direction_for_rotation(unsigned int rotation)145 static enum pixel_read_direction direction_for_rotation(unsigned int rotation)
146 {
147 struct drm_rect tmp_a, tmp_b;
148 int x, y;
149
150 /*
151 * Points A and B are depicted as zero-size rectangles on the CRTC.
152 * The CRTC writing direction is from A to B. The plane reading direction
153 * is discovered by inverse-transforming A and B.
154 * The reading direction is computed by rotating the vector AB (top-left to top-right) in a
155 * 1x1 square.
156 */
157
158 tmp_a = DRM_RECT_INIT(0, 0, 0, 0);
159 tmp_b = DRM_RECT_INIT(1, 0, 0, 0);
160 drm_rect_rotate_inv(&tmp_a, 1, 1, rotation);
161 drm_rect_rotate_inv(&tmp_b, 1, 1, rotation);
162
163 x = tmp_b.x1 - tmp_a.x1;
164 y = tmp_b.y1 - tmp_a.y1;
165
166 if (x == 1 && y == 0)
167 return READ_LEFT_TO_RIGHT;
168 else if (x == -1 && y == 0)
169 return READ_RIGHT_TO_LEFT;
170 else if (y == 1 && x == 0)
171 return READ_TOP_TO_BOTTOM;
172 else if (y == -1 && x == 0)
173 return READ_BOTTOM_TO_TOP;
174
175 WARN_ONCE(true, "The inverse of the rotation gives an incorrect direction.");
176 return READ_LEFT_TO_RIGHT;
177 }
178
179 /**
180 * clamp_line_coordinates() - Compute and clamp the coordinate to read and write during the blend
181 * process.
182 *
183 * @direction: direction of the reading
184 * @current_plane: current plane blended
185 * @src_line: source line of the reading. Only the top-left coordinate is used. This rectangle
186 * must be rotated and have a shape of 1*pixel_count if @direction is vertical and a shape of
187 * pixel_count*1 if @direction is horizontal.
188 * @src_x_start: x start coordinate for the line reading
189 * @src_y_start: y start coordinate for the line reading
190 * @dst_x_start: x coordinate to blend the read line
191 * @pixel_count: number of pixels to blend
192 *
193 * This function is mainly a safety net to avoid reading outside the source buffer. As the
194 * userspace should never ask to read outside the source plane, all the cases covered here should
195 * be dead code.
196 */
clamp_line_coordinates(enum pixel_read_direction direction,const struct vkms_plane_state * current_plane,const struct drm_rect * src_line,int * src_x_start,int * src_y_start,int * dst_x_start,int * pixel_count)197 static void clamp_line_coordinates(enum pixel_read_direction direction,
198 const struct vkms_plane_state *current_plane,
199 const struct drm_rect *src_line, int *src_x_start,
200 int *src_y_start, int *dst_x_start, int *pixel_count)
201 {
202 /* By default the start points are correct */
203 *src_x_start = src_line->x1;
204 *src_y_start = src_line->y1;
205 *dst_x_start = current_plane->frame_info->dst.x1;
206
207 /* Get the correct number of pixel to blend, it depends of the direction */
208 switch (direction) {
209 case READ_LEFT_TO_RIGHT:
210 case READ_RIGHT_TO_LEFT:
211 *pixel_count = drm_rect_width(src_line);
212 break;
213 case READ_BOTTOM_TO_TOP:
214 case READ_TOP_TO_BOTTOM:
215 *pixel_count = drm_rect_height(src_line);
216 break;
217 }
218
219 /*
220 * Clamp the coordinates to avoid reading outside the buffer
221 *
222 * This is mainly a security check to avoid reading outside the buffer, the userspace
223 * should never request to read outside the source buffer.
224 */
225 switch (direction) {
226 case READ_LEFT_TO_RIGHT:
227 case READ_RIGHT_TO_LEFT:
228 if (*src_x_start < 0) {
229 *pixel_count += *src_x_start;
230 *dst_x_start -= *src_x_start;
231 *src_x_start = 0;
232 }
233 if (*src_x_start + *pixel_count > current_plane->frame_info->fb->width)
234 *pixel_count = max(0, (int)current_plane->frame_info->fb->width -
235 *src_x_start);
236 break;
237 case READ_BOTTOM_TO_TOP:
238 case READ_TOP_TO_BOTTOM:
239 if (*src_y_start < 0) {
240 *pixel_count += *src_y_start;
241 *dst_x_start -= *src_y_start;
242 *src_y_start = 0;
243 }
244 if (*src_y_start + *pixel_count > current_plane->frame_info->fb->height)
245 *pixel_count = max(0, (int)current_plane->frame_info->fb->height -
246 *src_y_start);
247 break;
248 }
249 }
250
251 /**
252 * blend_line() - Blend a line from a plane to the output buffer
253 *
254 * @current_plane: current plane to work on
255 * @y: line to write in the output buffer
256 * @crtc_x_limit: width of the output buffer
257 * @stage_buffer: temporary buffer to convert the pixel line from the source buffer
258 * @output_buffer: buffer to blend the read line into.
259 */
blend_line(struct vkms_plane_state * current_plane,int y,int crtc_x_limit,struct line_buffer * stage_buffer,struct line_buffer * output_buffer)260 static void blend_line(struct vkms_plane_state *current_plane, int y,
261 int crtc_x_limit, struct line_buffer *stage_buffer,
262 struct line_buffer *output_buffer)
263 {
264 int src_x_start, src_y_start, dst_x_start, pixel_count;
265 struct drm_rect dst_line, tmp_src, src_line;
266
267 /* Avoid rendering useless lines */
268 if (y < current_plane->frame_info->dst.y1 ||
269 y >= current_plane->frame_info->dst.y2)
270 return;
271
272 /*
273 * dst_line is the line to copy. The initial coordinates are inside the
274 * destination framebuffer, and then drm_rect_* helpers are used to
275 * compute the correct position into the source framebuffer.
276 */
277 dst_line = DRM_RECT_INIT(current_plane->frame_info->dst.x1, y,
278 drm_rect_width(¤t_plane->frame_info->dst),
279 1);
280
281 drm_rect_fp_to_int(&tmp_src, ¤t_plane->frame_info->src);
282
283 /*
284 * [1]: Clamping src_line to the crtc_x_limit to avoid writing outside of
285 * the destination buffer
286 */
287 dst_line.x1 = max_t(int, dst_line.x1, 0);
288 dst_line.x2 = min_t(int, dst_line.x2, crtc_x_limit);
289 /* The destination is completely outside of the crtc. */
290 if (dst_line.x2 <= dst_line.x1)
291 return;
292
293 src_line = dst_line;
294
295 /*
296 * Transform the coordinate x/y from the crtc to coordinates into
297 * coordinates for the src buffer.
298 *
299 * - Cancel the offset of the dst buffer.
300 * - Invert the rotation. This assumes that
301 * dst = drm_rect_rotate(src, rotation) (dst and src have the
302 * same size, but can be rotated).
303 * - Apply the offset of the source rectangle to the coordinate.
304 */
305 drm_rect_translate(&src_line, -current_plane->frame_info->dst.x1,
306 -current_plane->frame_info->dst.y1);
307 drm_rect_rotate_inv(&src_line, drm_rect_width(&tmp_src),
308 drm_rect_height(&tmp_src),
309 current_plane->frame_info->rotation);
310 drm_rect_translate(&src_line, tmp_src.x1, tmp_src.y1);
311
312 /* Get the correct reading direction in the source buffer. */
313
314 enum pixel_read_direction direction =
315 direction_for_rotation(current_plane->frame_info->rotation);
316
317 /* [2]: Compute and clamp the number of pixel to read */
318 clamp_line_coordinates(direction, current_plane, &src_line, &src_x_start, &src_y_start,
319 &dst_x_start, &pixel_count);
320
321 if (pixel_count <= 0) {
322 /* Nothing to read, so avoid multiple function calls */
323 return;
324 }
325
326 /*
327 * Modify the starting point to take in account the rotation
328 *
329 * src_line is the top-left corner, so when reading READ_RIGHT_TO_LEFT or
330 * READ_BOTTOM_TO_TOP, it must be changed to the top-right/bottom-left
331 * corner.
332 */
333 if (direction == READ_RIGHT_TO_LEFT) {
334 // src_x_start is now the right point
335 src_x_start += pixel_count - 1;
336 } else if (direction == READ_BOTTOM_TO_TOP) {
337 // src_y_start is now the bottom point
338 src_y_start += pixel_count - 1;
339 }
340
341 /*
342 * Perform the conversion and the blending
343 *
344 * Here we know that the read line (x_start, y_start, pixel_count) is
345 * inside the source buffer [2] and we don't write outside the stage
346 * buffer [1].
347 */
348 current_plane->pixel_read_line(current_plane, src_x_start, src_y_start, direction,
349 pixel_count, &stage_buffer->pixels[dst_x_start]);
350
351 pre_mul_alpha_blend(stage_buffer, output_buffer,
352 dst_x_start, pixel_count);
353 }
354
355 /**
356 * blend - blend the pixels from all planes and compute crc
357 * @wb: The writeback frame buffer metadata
358 * @crtc_state: The crtc state
359 * @crc32: The crc output of the final frame
360 * @output_buffer: A buffer of a row that will receive the result of the blend(s)
361 * @stage_buffer: The line with the pixels from plane being blend to the output
362 * @row_size: The size, in bytes, of a single row
363 *
364 * This function blends the pixels (Using the `pre_mul_alpha_blend`)
365 * from all planes, calculates the crc32 of the output from the former step,
366 * and, if necessary, convert and store the output to the writeback buffer.
367 */
blend(struct vkms_writeback_job * wb,struct vkms_crtc_state * crtc_state,u32 * crc32,struct line_buffer * stage_buffer,struct line_buffer * output_buffer,size_t row_size)368 static void blend(struct vkms_writeback_job *wb,
369 struct vkms_crtc_state *crtc_state,
370 u32 *crc32, struct line_buffer *stage_buffer,
371 struct line_buffer *output_buffer, size_t row_size)
372 {
373 struct vkms_plane_state **plane = crtc_state->active_planes;
374 u32 n_active_planes = crtc_state->num_active_planes;
375
376 const struct pixel_argb_u16 background_color = { .a = 0xffff };
377
378 int crtc_y_limit = crtc_state->base.mode.vdisplay;
379 int crtc_x_limit = crtc_state->base.mode.hdisplay;
380
381 /*
382 * The planes are composed line-by-line to avoid heavy memory usage. It is a necessary
383 * complexity to avoid poor blending performance.
384 *
385 * The function pixel_read_line callback is used to read a line, using an efficient
386 * algorithm for a specific format, into the staging buffer.
387 */
388 for (int y = 0; y < crtc_y_limit; y++) {
389 fill_background(&background_color, output_buffer);
390
391 /* The active planes are composed associatively in z-order. */
392 for (size_t i = 0; i < n_active_planes; i++) {
393 blend_line(plane[i], y, crtc_x_limit, stage_buffer, output_buffer);
394 }
395
396 apply_lut(crtc_state, output_buffer);
397
398 *crc32 = crc32_le(*crc32, (void *)output_buffer->pixels, row_size);
399
400 if (wb)
401 vkms_writeback_row(wb, output_buffer, y);
402 }
403 }
404
check_format_funcs(struct vkms_crtc_state * crtc_state,struct vkms_writeback_job * active_wb)405 static int check_format_funcs(struct vkms_crtc_state *crtc_state,
406 struct vkms_writeback_job *active_wb)
407 {
408 struct vkms_plane_state **planes = crtc_state->active_planes;
409 u32 n_active_planes = crtc_state->num_active_planes;
410
411 for (size_t i = 0; i < n_active_planes; i++)
412 if (!planes[i]->pixel_read_line)
413 return -1;
414
415 if (active_wb && !active_wb->pixel_write)
416 return -1;
417
418 return 0;
419 }
420
check_iosys_map(struct vkms_crtc_state * crtc_state)421 static int check_iosys_map(struct vkms_crtc_state *crtc_state)
422 {
423 struct vkms_plane_state **plane_state = crtc_state->active_planes;
424 u32 n_active_planes = crtc_state->num_active_planes;
425
426 for (size_t i = 0; i < n_active_planes; i++)
427 if (iosys_map_is_null(&plane_state[i]->frame_info->map[0]))
428 return -1;
429
430 return 0;
431 }
432
compose_active_planes(struct vkms_writeback_job * active_wb,struct vkms_crtc_state * crtc_state,u32 * crc32)433 static int compose_active_planes(struct vkms_writeback_job *active_wb,
434 struct vkms_crtc_state *crtc_state,
435 u32 *crc32)
436 {
437 size_t line_width, pixel_size = sizeof(struct pixel_argb_u16);
438 struct line_buffer output_buffer, stage_buffer;
439 int ret = 0;
440
441 /*
442 * This check exists so we can call `crc32_le` for the entire line
443 * instead doing it for each channel of each pixel in case
444 * `struct `pixel_argb_u16` had any gap added by the compiler
445 * between the struct fields.
446 */
447 static_assert(sizeof(struct pixel_argb_u16) == 8);
448
449 if (WARN_ON(check_iosys_map(crtc_state)))
450 return -EINVAL;
451
452 if (WARN_ON(check_format_funcs(crtc_state, active_wb)))
453 return -EINVAL;
454
455 line_width = crtc_state->base.mode.hdisplay;
456 stage_buffer.n_pixels = line_width;
457 output_buffer.n_pixels = line_width;
458
459 stage_buffer.pixels = kvmalloc(line_width * pixel_size, GFP_KERNEL);
460 if (!stage_buffer.pixels) {
461 DRM_ERROR("Cannot allocate memory for the output line buffer");
462 return -ENOMEM;
463 }
464
465 output_buffer.pixels = kvmalloc(line_width * pixel_size, GFP_KERNEL);
466 if (!output_buffer.pixels) {
467 DRM_ERROR("Cannot allocate memory for intermediate line buffer");
468 ret = -ENOMEM;
469 goto free_stage_buffer;
470 }
471
472 blend(active_wb, crtc_state, crc32, &stage_buffer,
473 &output_buffer, line_width * pixel_size);
474
475 kvfree(output_buffer.pixels);
476 free_stage_buffer:
477 kvfree(stage_buffer.pixels);
478
479 return ret;
480 }
481
482 /**
483 * vkms_composer_worker - ordered work_struct to compute CRC
484 *
485 * @work: work_struct
486 *
487 * Work handler for composing and computing CRCs. work_struct scheduled in
488 * an ordered workqueue that's periodically scheduled to run by
489 * vkms_vblank_simulate() and flushed at vkms_atomic_commit_tail().
490 */
vkms_composer_worker(struct work_struct * work)491 void vkms_composer_worker(struct work_struct *work)
492 {
493 struct vkms_crtc_state *crtc_state = container_of(work,
494 struct vkms_crtc_state,
495 composer_work);
496 struct drm_crtc *crtc = crtc_state->base.crtc;
497 struct vkms_writeback_job *active_wb = crtc_state->active_writeback;
498 struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
499 bool crc_pending, wb_pending;
500 u64 frame_start, frame_end;
501 u32 crc32 = 0;
502 int ret;
503
504 spin_lock_irq(&out->composer_lock);
505 frame_start = crtc_state->frame_start;
506 frame_end = crtc_state->frame_end;
507 crc_pending = crtc_state->crc_pending;
508 wb_pending = crtc_state->wb_pending;
509 crtc_state->frame_start = 0;
510 crtc_state->frame_end = 0;
511 crtc_state->crc_pending = false;
512
513 if (crtc->state->gamma_lut) {
514 s64 max_lut_index_fp;
515 s64 u16_max_fp = drm_int2fixp(0xffff);
516
517 crtc_state->gamma_lut.base = (struct drm_color_lut *)crtc->state->gamma_lut->data;
518 crtc_state->gamma_lut.lut_length =
519 crtc->state->gamma_lut->length / sizeof(struct drm_color_lut);
520 max_lut_index_fp = drm_int2fixp(crtc_state->gamma_lut.lut_length - 1);
521 crtc_state->gamma_lut.channel_value2index_ratio = drm_fixp_div(max_lut_index_fp,
522 u16_max_fp);
523
524 } else {
525 crtc_state->gamma_lut.base = NULL;
526 }
527
528 spin_unlock_irq(&out->composer_lock);
529
530 /*
531 * We raced with the vblank hrtimer and previous work already computed
532 * the crc, nothing to do.
533 */
534 if (!crc_pending)
535 return;
536
537 if (wb_pending)
538 ret = compose_active_planes(active_wb, crtc_state, &crc32);
539 else
540 ret = compose_active_planes(NULL, crtc_state, &crc32);
541
542 if (ret)
543 return;
544
545 if (wb_pending) {
546 drm_writeback_signal_completion(&out->wb_connector, 0);
547 spin_lock_irq(&out->composer_lock);
548 crtc_state->wb_pending = false;
549 spin_unlock_irq(&out->composer_lock);
550 }
551
552 /*
553 * The worker can fall behind the vblank hrtimer, make sure we catch up.
554 */
555 while (frame_start <= frame_end)
556 drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32);
557 }
558
559 static const char *const pipe_crc_sources[] = { "auto" };
560
vkms_get_crc_sources(struct drm_crtc * crtc,size_t * count)561 const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
562 size_t *count)
563 {
564 *count = ARRAY_SIZE(pipe_crc_sources);
565 return pipe_crc_sources;
566 }
567
vkms_crc_parse_source(const char * src_name,bool * enabled)568 static int vkms_crc_parse_source(const char *src_name, bool *enabled)
569 {
570 int ret = 0;
571
572 if (!src_name) {
573 *enabled = false;
574 } else if (strcmp(src_name, "auto") == 0) {
575 *enabled = true;
576 } else {
577 *enabled = false;
578 ret = -EINVAL;
579 }
580
581 return ret;
582 }
583
vkms_verify_crc_source(struct drm_crtc * crtc,const char * src_name,size_t * values_cnt)584 int vkms_verify_crc_source(struct drm_crtc *crtc, const char *src_name,
585 size_t *values_cnt)
586 {
587 bool enabled;
588
589 if (vkms_crc_parse_source(src_name, &enabled) < 0) {
590 DRM_DEBUG_DRIVER("unknown source %s\n", src_name);
591 return -EINVAL;
592 }
593
594 *values_cnt = 1;
595
596 return 0;
597 }
598
vkms_set_composer(struct vkms_output * out,bool enabled)599 void vkms_set_composer(struct vkms_output *out, bool enabled)
600 {
601 bool old_enabled;
602
603 if (enabled)
604 drm_crtc_vblank_get(&out->crtc);
605
606 spin_lock_irq(&out->lock);
607 old_enabled = out->composer_enabled;
608 out->composer_enabled = enabled;
609 spin_unlock_irq(&out->lock);
610
611 if (old_enabled)
612 drm_crtc_vblank_put(&out->crtc);
613 }
614
vkms_set_crc_source(struct drm_crtc * crtc,const char * src_name)615 int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name)
616 {
617 struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
618 bool enabled = false;
619 int ret = 0;
620
621 ret = vkms_crc_parse_source(src_name, &enabled);
622
623 vkms_set_composer(out, enabled);
624
625 return ret;
626 }
627