2 * Copyright © 2014 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
25 * DOC: Frame Buffer Compression (FBC)
27 * FBC tries to save memory bandwidth (and so power consumption) by
28 * compressing the amount of memory used by the display. It is total
29 * transparent to user space and completely handled in the kernel.
31 * The benefits of FBC are mostly visible with solid backgrounds and
32 * variation-less patterns. It comes from keeping the memory footprint small
33 * and having fewer memory pages opened and accessed for refreshing the display.
35 * i915 is responsible to reserve stolen memory for FBC and configure its
36 * offset on proper registers. The hardware takes care of all
37 * compress/decompress. However there are many known cases where we have to
38 * forcibly disable it to allow proper screen updates.
41 #include "intel_drv.h"
44 static inline bool fbc_supported(struct drm_i915_private
*dev_priv
)
46 return HAS_FBC(dev_priv
);
49 static inline bool fbc_on_pipe_a_only(struct drm_i915_private
*dev_priv
)
51 return IS_HASWELL(dev_priv
) || INTEL_GEN(dev_priv
) >= 8;
54 static inline bool fbc_on_plane_a_only(struct drm_i915_private
*dev_priv
)
56 return INTEL_GEN(dev_priv
) < 4;
59 static inline bool no_fbc_on_multiple_pipes(struct drm_i915_private
*dev_priv
)
61 return INTEL_GEN(dev_priv
) <= 3;
65 * In some platforms where the CRTC's x:0/y:0 coordinates doesn't match the
66 * frontbuffer's x:0/y:0 coordinates we lie to the hardware about the plane's
67 * origin so the x and y offsets can actually fit the registers. As a
68 * consequence, the fence doesn't really start exactly at the display plane
69 * address we program because it starts at the real start of the buffer, so we
70 * have to take this into consideration here.
72 static unsigned int get_crtc_fence_y_offset(struct intel_crtc
*crtc
)
74 return crtc
->base
.y
- crtc
->adjusted_y
;
78 * For SKL+, the plane source size used by the hardware is based on the value we
79 * write to the PLANE_SIZE register. For BDW-, the hardware looks at the value
80 * we wrote to PIPESRC.
82 static void intel_fbc_get_plane_source_size(struct intel_fbc_state_cache
*cache
,
83 int *width
, int *height
)
86 *width
= cache
->plane
.src_w
;
88 *height
= cache
->plane
.src_h
;
91 static int intel_fbc_calculate_cfb_size(struct drm_i915_private
*dev_priv
,
92 struct intel_fbc_state_cache
*cache
)
96 intel_fbc_get_plane_source_size(cache
, NULL
, &lines
);
97 if (INTEL_GEN(dev_priv
) == 7)
98 lines
= min(lines
, 2048);
99 else if (INTEL_GEN(dev_priv
) >= 8)
100 lines
= min(lines
, 2560);
102 /* Hardware needs the full buffer stride, not just the active area. */
103 return lines
* cache
->fb
.stride
;
106 static void i8xx_fbc_deactivate(struct drm_i915_private
*dev_priv
)
110 /* Disable compression */
111 fbc_ctl
= I915_READ(FBC_CONTROL
);
112 if ((fbc_ctl
& FBC_CTL_EN
) == 0)
115 fbc_ctl
&= ~FBC_CTL_EN
;
116 I915_WRITE(FBC_CONTROL
, fbc_ctl
);
118 /* Wait for compressing bit to clear */
119 if (intel_wait_for_register(dev_priv
,
120 FBC_STATUS
, FBC_STAT_COMPRESSING
, 0,
122 DRM_DEBUG_KMS("FBC idle timed out\n");
127 static void i8xx_fbc_activate(struct drm_i915_private
*dev_priv
)
129 struct intel_fbc_reg_params
*params
= &dev_priv
->fbc
.params
;
134 /* Note: fbc.threshold == 1 for i8xx */
135 cfb_pitch
= params
->cfb_size
/ FBC_LL_SIZE
;
136 if (params
->fb
.stride
< cfb_pitch
)
137 cfb_pitch
= params
->fb
.stride
;
139 /* FBC_CTL wants 32B or 64B units */
140 if (IS_GEN2(dev_priv
))
141 cfb_pitch
= (cfb_pitch
/ 32) - 1;
143 cfb_pitch
= (cfb_pitch
/ 64) - 1;
146 for (i
= 0; i
< (FBC_LL_SIZE
/ 32) + 1; i
++)
147 I915_WRITE(FBC_TAG(i
), 0);
149 if (IS_GEN4(dev_priv
)) {
153 fbc_ctl2
= FBC_CTL_FENCE_DBL
| FBC_CTL_IDLE_IMM
| FBC_CTL_CPU_FENCE
;
154 fbc_ctl2
|= FBC_CTL_PLANE(params
->crtc
.plane
);
155 I915_WRITE(FBC_CONTROL2
, fbc_ctl2
);
156 I915_WRITE(FBC_FENCE_OFF
, params
->crtc
.fence_y_offset
);
160 fbc_ctl
= I915_READ(FBC_CONTROL
);
161 fbc_ctl
&= 0x3fff << FBC_CTL_INTERVAL_SHIFT
;
162 fbc_ctl
|= FBC_CTL_EN
| FBC_CTL_PERIODIC
;
163 if (IS_I945GM(dev_priv
))
164 fbc_ctl
|= FBC_CTL_C3_IDLE
; /* 945 needs special SR handling */
165 fbc_ctl
|= (cfb_pitch
& 0xff) << FBC_CTL_STRIDE_SHIFT
;
166 fbc_ctl
|= params
->vma
->fence
->id
;
167 I915_WRITE(FBC_CONTROL
, fbc_ctl
);
170 static bool i8xx_fbc_is_active(struct drm_i915_private
*dev_priv
)
172 return I915_READ(FBC_CONTROL
) & FBC_CTL_EN
;
175 static void g4x_fbc_activate(struct drm_i915_private
*dev_priv
)
177 struct intel_fbc_reg_params
*params
= &dev_priv
->fbc
.params
;
180 dpfc_ctl
= DPFC_CTL_PLANE(params
->crtc
.plane
) | DPFC_SR_EN
;
181 if (params
->fb
.format
->cpp
[0] == 2)
182 dpfc_ctl
|= DPFC_CTL_LIMIT_2X
;
184 dpfc_ctl
|= DPFC_CTL_LIMIT_1X
;
186 if (params
->vma
->fence
) {
187 dpfc_ctl
|= DPFC_CTL_FENCE_EN
| params
->vma
->fence
->id
;
188 I915_WRITE(DPFC_FENCE_YOFF
, params
->crtc
.fence_y_offset
);
190 I915_WRITE(DPFC_FENCE_YOFF
, 0);
194 I915_WRITE(DPFC_CONTROL
, dpfc_ctl
| DPFC_CTL_EN
);
197 static void g4x_fbc_deactivate(struct drm_i915_private
*dev_priv
)
201 /* Disable compression */
202 dpfc_ctl
= I915_READ(DPFC_CONTROL
);
203 if (dpfc_ctl
& DPFC_CTL_EN
) {
204 dpfc_ctl
&= ~DPFC_CTL_EN
;
205 I915_WRITE(DPFC_CONTROL
, dpfc_ctl
);
209 static bool g4x_fbc_is_active(struct drm_i915_private
*dev_priv
)
211 return I915_READ(DPFC_CONTROL
) & DPFC_CTL_EN
;
214 /* This function forces a CFB recompression through the nuke operation. */
215 static void intel_fbc_recompress(struct drm_i915_private
*dev_priv
)
217 I915_WRITE(MSG_FBC_REND_STATE
, FBC_REND_NUKE
);
218 POSTING_READ(MSG_FBC_REND_STATE
);
221 static void ilk_fbc_activate(struct drm_i915_private
*dev_priv
)
223 struct intel_fbc_reg_params
*params
= &dev_priv
->fbc
.params
;
225 int threshold
= dev_priv
->fbc
.threshold
;
227 dpfc_ctl
= DPFC_CTL_PLANE(params
->crtc
.plane
);
228 if (params
->fb
.format
->cpp
[0] == 2)
234 dpfc_ctl
|= DPFC_CTL_LIMIT_4X
;
237 dpfc_ctl
|= DPFC_CTL_LIMIT_2X
;
240 dpfc_ctl
|= DPFC_CTL_LIMIT_1X
;
244 if (params
->vma
->fence
) {
245 dpfc_ctl
|= DPFC_CTL_FENCE_EN
;
246 if (IS_GEN5(dev_priv
))
247 dpfc_ctl
|= params
->vma
->fence
->id
;
248 if (IS_GEN6(dev_priv
)) {
249 I915_WRITE(SNB_DPFC_CTL_SA
,
250 SNB_CPU_FENCE_ENABLE
|
251 params
->vma
->fence
->id
);
252 I915_WRITE(DPFC_CPU_FENCE_OFFSET
,
253 params
->crtc
.fence_y_offset
);
256 if (IS_GEN6(dev_priv
)) {
257 I915_WRITE(SNB_DPFC_CTL_SA
, 0);
258 I915_WRITE(DPFC_CPU_FENCE_OFFSET
, 0);
262 I915_WRITE(ILK_DPFC_FENCE_YOFF
, params
->crtc
.fence_y_offset
);
263 I915_WRITE(ILK_FBC_RT_BASE
,
264 i915_ggtt_offset(params
->vma
) | ILK_FBC_RT_VALID
);
266 I915_WRITE(ILK_DPFC_CONTROL
, dpfc_ctl
| DPFC_CTL_EN
);
268 intel_fbc_recompress(dev_priv
);
271 static void ilk_fbc_deactivate(struct drm_i915_private
*dev_priv
)
275 /* Disable compression */
276 dpfc_ctl
= I915_READ(ILK_DPFC_CONTROL
);
277 if (dpfc_ctl
& DPFC_CTL_EN
) {
278 dpfc_ctl
&= ~DPFC_CTL_EN
;
279 I915_WRITE(ILK_DPFC_CONTROL
, dpfc_ctl
);
283 static bool ilk_fbc_is_active(struct drm_i915_private
*dev_priv
)
285 return I915_READ(ILK_DPFC_CONTROL
) & DPFC_CTL_EN
;
288 static void gen7_fbc_activate(struct drm_i915_private
*dev_priv
)
290 struct intel_fbc_reg_params
*params
= &dev_priv
->fbc
.params
;
292 int threshold
= dev_priv
->fbc
.threshold
;
295 if (IS_IVYBRIDGE(dev_priv
))
296 dpfc_ctl
|= IVB_DPFC_CTL_PLANE(params
->crtc
.plane
);
298 if (params
->fb
.format
->cpp
[0] == 2)
304 dpfc_ctl
|= DPFC_CTL_LIMIT_4X
;
307 dpfc_ctl
|= DPFC_CTL_LIMIT_2X
;
310 dpfc_ctl
|= DPFC_CTL_LIMIT_1X
;
314 if (params
->vma
->fence
) {
315 dpfc_ctl
|= IVB_DPFC_CTL_FENCE_EN
;
316 I915_WRITE(SNB_DPFC_CTL_SA
,
317 SNB_CPU_FENCE_ENABLE
|
318 params
->vma
->fence
->id
);
319 I915_WRITE(DPFC_CPU_FENCE_OFFSET
, params
->crtc
.fence_y_offset
);
321 I915_WRITE(SNB_DPFC_CTL_SA
,0);
322 I915_WRITE(DPFC_CPU_FENCE_OFFSET
, 0);
325 if (dev_priv
->fbc
.false_color
)
326 dpfc_ctl
|= FBC_CTL_FALSE_COLOR
;
328 if (IS_IVYBRIDGE(dev_priv
)) {
329 /* WaFbcAsynchFlipDisableFbcQueue:ivb */
330 I915_WRITE(ILK_DISPLAY_CHICKEN1
,
331 I915_READ(ILK_DISPLAY_CHICKEN1
) |
333 } else if (IS_HASWELL(dev_priv
) || IS_BROADWELL(dev_priv
)) {
334 /* WaFbcAsynchFlipDisableFbcQueue:hsw,bdw */
335 I915_WRITE(CHICKEN_PIPESL_1(params
->crtc
.pipe
),
336 I915_READ(CHICKEN_PIPESL_1(params
->crtc
.pipe
)) |
340 I915_WRITE(ILK_DPFC_CONTROL
, dpfc_ctl
| DPFC_CTL_EN
);
342 intel_fbc_recompress(dev_priv
);
345 static bool intel_fbc_hw_is_active(struct drm_i915_private
*dev_priv
)
347 if (INTEL_GEN(dev_priv
) >= 5)
348 return ilk_fbc_is_active(dev_priv
);
349 else if (IS_GM45(dev_priv
))
350 return g4x_fbc_is_active(dev_priv
);
352 return i8xx_fbc_is_active(dev_priv
);
355 static void intel_fbc_hw_activate(struct drm_i915_private
*dev_priv
)
357 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
361 if (INTEL_GEN(dev_priv
) >= 7)
362 gen7_fbc_activate(dev_priv
);
363 else if (INTEL_GEN(dev_priv
) >= 5)
364 ilk_fbc_activate(dev_priv
);
365 else if (IS_GM45(dev_priv
))
366 g4x_fbc_activate(dev_priv
);
368 i8xx_fbc_activate(dev_priv
);
371 static void intel_fbc_hw_deactivate(struct drm_i915_private
*dev_priv
)
373 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
377 if (INTEL_GEN(dev_priv
) >= 5)
378 ilk_fbc_deactivate(dev_priv
);
379 else if (IS_GM45(dev_priv
))
380 g4x_fbc_deactivate(dev_priv
);
382 i8xx_fbc_deactivate(dev_priv
);
386 * intel_fbc_is_active - Is FBC active?
387 * @dev_priv: i915 device instance
389 * This function is used to verify the current state of FBC.
391 * FIXME: This should be tracked in the plane config eventually
392 * instead of queried at runtime for most callers.
394 bool intel_fbc_is_active(struct drm_i915_private
*dev_priv
)
396 return dev_priv
->fbc
.active
;
399 static void intel_fbc_work_fn(struct work_struct
*__work
)
401 struct drm_i915_private
*dev_priv
=
402 container_of(__work
, struct drm_i915_private
, fbc
.work
.work
);
403 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
404 struct intel_fbc_work
*work
= &fbc
->work
;
405 struct intel_crtc
*crtc
= fbc
->crtc
;
406 struct drm_vblank_crtc
*vblank
= &dev_priv
->drm
.vblank
[crtc
->pipe
];
408 if (drm_crtc_vblank_get(&crtc
->base
)) {
409 DRM_ERROR("vblank not available for FBC on pipe %c\n",
410 pipe_name(crtc
->pipe
));
412 mutex_lock(&fbc
->lock
);
413 work
->scheduled
= false;
414 mutex_unlock(&fbc
->lock
);
419 /* Delay the actual enabling to let pageflipping cease and the
420 * display to settle before starting the compression. Note that
421 * this delay also serves a second purpose: it allows for a
422 * vblank to pass after disabling the FBC before we attempt
423 * to modify the control registers.
425 * WaFbcWaitForVBlankBeforeEnable:ilk,snb
427 * It is also worth mentioning that since work->scheduled_vblank can be
428 * updated multiple times by the other threads, hitting the timeout is
429 * not an error condition. We'll just end up hitting the "goto retry"
432 wait_event_timeout(vblank
->queue
,
433 drm_crtc_vblank_count(&crtc
->base
) != work
->scheduled_vblank
,
434 msecs_to_jiffies(50));
436 mutex_lock(&fbc
->lock
);
438 /* Were we cancelled? */
439 if (!work
->scheduled
)
442 /* Were we delayed again while this function was sleeping? */
443 if (drm_crtc_vblank_count(&crtc
->base
) == work
->scheduled_vblank
) {
444 mutex_unlock(&fbc
->lock
);
448 intel_fbc_hw_activate(dev_priv
);
450 work
->scheduled
= false;
453 mutex_unlock(&fbc
->lock
);
454 drm_crtc_vblank_put(&crtc
->base
);
457 static void intel_fbc_schedule_activation(struct intel_crtc
*crtc
)
459 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
460 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
461 struct intel_fbc_work
*work
= &fbc
->work
;
463 WARN_ON(!mutex_is_locked(&fbc
->lock
));
465 if (drm_crtc_vblank_get(&crtc
->base
)) {
466 DRM_ERROR("vblank not available for FBC on pipe %c\n",
467 pipe_name(crtc
->pipe
));
471 /* It is useless to call intel_fbc_cancel_work() or cancel_work() in
472 * this function since we're not releasing fbc.lock, so it won't have an
473 * opportunity to grab it to discover that it was cancelled. So we just
474 * update the expected jiffy count. */
475 work
->scheduled
= true;
476 work
->scheduled_vblank
= drm_crtc_vblank_count(&crtc
->base
);
477 drm_crtc_vblank_put(&crtc
->base
);
479 schedule_work(&work
->work
);
482 static void intel_fbc_deactivate(struct drm_i915_private
*dev_priv
)
484 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
486 WARN_ON(!mutex_is_locked(&fbc
->lock
));
488 /* Calling cancel_work() here won't help due to the fact that the work
489 * function grabs fbc->lock. Just set scheduled to false so the work
490 * function can know it was cancelled. */
491 fbc
->work
.scheduled
= false;
494 intel_fbc_hw_deactivate(dev_priv
);
497 static bool multiple_pipes_ok(struct intel_crtc
*crtc
,
498 struct intel_plane_state
*plane_state
)
500 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
501 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
502 enum pipe pipe
= crtc
->pipe
;
504 /* Don't even bother tracking anything we don't need. */
505 if (!no_fbc_on_multiple_pipes(dev_priv
))
508 if (plane_state
->base
.visible
)
509 fbc
->visible_pipes_mask
|= (1 << pipe
);
511 fbc
->visible_pipes_mask
&= ~(1 << pipe
);
513 return (fbc
->visible_pipes_mask
& ~(1 << pipe
)) != 0;
516 static int find_compression_threshold(struct drm_i915_private
*dev_priv
,
517 struct drm_mm_node
*node
,
521 struct i915_ggtt
*ggtt
= &dev_priv
->ggtt
;
522 int compression_threshold
= 1;
526 /* The FBC hardware for BDW/SKL doesn't have access to the stolen
527 * reserved range size, so it always assumes the maximum (8mb) is used.
528 * If we enable FBC using a CFB on that memory range we'll get FIFO
529 * underruns, even if that range is not reserved by the BIOS. */
530 if (IS_BROADWELL(dev_priv
) || IS_GEN9_BC(dev_priv
))
531 end
= ggtt
->stolen_size
- 8 * 1024 * 1024;
535 /* HACK: This code depends on what we will do in *_enable_fbc. If that
536 * code changes, this code needs to change as well.
538 * The enable_fbc code will attempt to use one of our 2 compression
539 * thresholds, therefore, in that case, we only have 1 resort.
542 /* Try to over-allocate to reduce reallocations and fragmentation. */
543 ret
= i915_gem_stolen_insert_node_in_range(dev_priv
, node
, size
<<= 1,
546 return compression_threshold
;
549 /* HW's ability to limit the CFB is 1:4 */
550 if (compression_threshold
> 4 ||
551 (fb_cpp
== 2 && compression_threshold
== 2))
554 ret
= i915_gem_stolen_insert_node_in_range(dev_priv
, node
, size
>>= 1,
556 if (ret
&& INTEL_GEN(dev_priv
) <= 4) {
559 compression_threshold
<<= 1;
562 return compression_threshold
;
566 static int intel_fbc_alloc_cfb(struct intel_crtc
*crtc
)
568 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
569 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
570 struct drm_mm_node
*uninitialized_var(compressed_llb
);
571 int size
, fb_cpp
, ret
;
573 WARN_ON(drm_mm_node_allocated(&fbc
->compressed_fb
));
575 size
= intel_fbc_calculate_cfb_size(dev_priv
, &fbc
->state_cache
);
576 fb_cpp
= fbc
->state_cache
.fb
.format
->cpp
[0];
578 ret
= find_compression_threshold(dev_priv
, &fbc
->compressed_fb
,
583 DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");
587 fbc
->threshold
= ret
;
589 if (INTEL_GEN(dev_priv
) >= 5)
590 I915_WRITE(ILK_DPFC_CB_BASE
, fbc
->compressed_fb
.start
);
591 else if (IS_GM45(dev_priv
)) {
592 I915_WRITE(DPFC_CB_BASE
, fbc
->compressed_fb
.start
);
594 compressed_llb
= kzalloc(sizeof(*compressed_llb
), GFP_KERNEL
);
598 ret
= i915_gem_stolen_insert_node(dev_priv
, compressed_llb
,
603 fbc
->compressed_llb
= compressed_llb
;
605 I915_WRITE(FBC_CFB_BASE
,
606 dev_priv
->mm
.stolen_base
+ fbc
->compressed_fb
.start
);
607 I915_WRITE(FBC_LL_BASE
,
608 dev_priv
->mm
.stolen_base
+ compressed_llb
->start
);
611 DRM_DEBUG_KMS("reserved %llu bytes of contiguous stolen space for FBC, threshold: %d\n",
612 fbc
->compressed_fb
.size
, fbc
->threshold
);
617 kfree(compressed_llb
);
618 i915_gem_stolen_remove_node(dev_priv
, &fbc
->compressed_fb
);
620 if (drm_mm_initialized(&dev_priv
->mm
.stolen
))
621 pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size
);
625 static void __intel_fbc_cleanup_cfb(struct drm_i915_private
*dev_priv
)
627 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
629 if (drm_mm_node_allocated(&fbc
->compressed_fb
))
630 i915_gem_stolen_remove_node(dev_priv
, &fbc
->compressed_fb
);
632 if (fbc
->compressed_llb
) {
633 i915_gem_stolen_remove_node(dev_priv
, fbc
->compressed_llb
);
634 kfree(fbc
->compressed_llb
);
638 void intel_fbc_cleanup_cfb(struct drm_i915_private
*dev_priv
)
640 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
642 if (!fbc_supported(dev_priv
))
645 mutex_lock(&fbc
->lock
);
646 __intel_fbc_cleanup_cfb(dev_priv
);
647 mutex_unlock(&fbc
->lock
);
650 static bool stride_is_valid(struct drm_i915_private
*dev_priv
,
653 /* These should have been caught earlier. */
654 WARN_ON(stride
< 512);
655 WARN_ON((stride
& (64 - 1)) != 0);
657 /* Below are the additional FBC restrictions. */
659 if (IS_GEN2(dev_priv
) || IS_GEN3(dev_priv
))
660 return stride
== 4096 || stride
== 8192;
662 if (IS_GEN4(dev_priv
) && !IS_G4X(dev_priv
) && stride
< 2048)
671 static bool pixel_format_is_valid(struct drm_i915_private
*dev_priv
,
672 uint32_t pixel_format
)
674 switch (pixel_format
) {
675 case DRM_FORMAT_XRGB8888
:
676 case DRM_FORMAT_XBGR8888
:
678 case DRM_FORMAT_XRGB1555
:
679 case DRM_FORMAT_RGB565
:
680 /* 16bpp not supported on gen2 */
681 if (IS_GEN2(dev_priv
))
683 /* WaFbcOnly1to1Ratio:ctg */
684 if (IS_G4X(dev_priv
))
693 * For some reason, the hardware tracking starts looking at whatever we
694 * programmed as the display plane base address register. It does not look at
695 * the X and Y offset registers. That's why we look at the crtc->adjusted{x,y}
696 * variables instead of just looking at the pipe/plane size.
698 static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc
*crtc
)
700 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
701 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
702 unsigned int effective_w
, effective_h
, max_w
, max_h
;
704 if (INTEL_GEN(dev_priv
) >= 8 || IS_HASWELL(dev_priv
)) {
707 } else if (IS_G4X(dev_priv
) || INTEL_GEN(dev_priv
) >= 5) {
715 intel_fbc_get_plane_source_size(&fbc
->state_cache
, &effective_w
,
717 effective_w
+= crtc
->adjusted_x
;
718 effective_h
+= crtc
->adjusted_y
;
720 return effective_w
<= max_w
&& effective_h
<= max_h
;
723 static void intel_fbc_update_state_cache(struct intel_crtc
*crtc
,
724 struct intel_crtc_state
*crtc_state
,
725 struct intel_plane_state
*plane_state
)
727 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
728 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
729 struct intel_fbc_state_cache
*cache
= &fbc
->state_cache
;
730 struct drm_framebuffer
*fb
= plane_state
->base
.fb
;
734 cache
->crtc
.mode_flags
= crtc_state
->base
.adjusted_mode
.flags
;
735 if (IS_HASWELL(dev_priv
) || IS_BROADWELL(dev_priv
))
736 cache
->crtc
.hsw_bdw_pixel_rate
= crtc_state
->pixel_rate
;
738 cache
->plane
.rotation
= plane_state
->base
.rotation
;
740 * Src coordinates are already rotated by 270 degrees for
741 * the 90/270 degree plane rotation cases (to match the
742 * GTT mapping), hence no need to account for rotation here.
744 cache
->plane
.src_w
= drm_rect_width(&plane_state
->base
.src
) >> 16;
745 cache
->plane
.src_h
= drm_rect_height(&plane_state
->base
.src
) >> 16;
746 cache
->plane
.visible
= plane_state
->base
.visible
;
748 if (!cache
->plane
.visible
)
751 cache
->fb
.format
= fb
->format
;
752 cache
->fb
.stride
= fb
->pitches
[0];
754 cache
->vma
= plane_state
->vma
;
757 static bool intel_fbc_can_activate(struct intel_crtc
*crtc
)
759 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
760 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
761 struct intel_fbc_state_cache
*cache
= &fbc
->state_cache
;
763 /* We don't need to use a state cache here since this information is
764 * global for all CRTC.
766 if (fbc
->underrun_detected
) {
767 fbc
->no_fbc_reason
= "underrun detected";
772 fbc
->no_fbc_reason
= "primary plane not visible";
776 if ((cache
->crtc
.mode_flags
& DRM_MODE_FLAG_INTERLACE
) ||
777 (cache
->crtc
.mode_flags
& DRM_MODE_FLAG_DBLSCAN
)) {
778 fbc
->no_fbc_reason
= "incompatible mode";
782 if (!intel_fbc_hw_tracking_covers_screen(crtc
)) {
783 fbc
->no_fbc_reason
= "mode too large for compression";
787 /* The use of a CPU fence is mandatory in order to detect writes
788 * by the CPU to the scanout and trigger updates to the FBC.
790 * Note that is possible for a tiled surface to be unmappable (and
791 * so have no fence associated with it) due to aperture constaints
792 * at the time of pinning.
794 if (!cache
->vma
->fence
) {
795 fbc
->no_fbc_reason
= "framebuffer not tiled or fenced";
798 if (INTEL_GEN(dev_priv
) <= 4 && !IS_G4X(dev_priv
) &&
799 cache
->plane
.rotation
!= DRM_MODE_ROTATE_0
) {
800 fbc
->no_fbc_reason
= "rotation unsupported";
804 if (!stride_is_valid(dev_priv
, cache
->fb
.stride
)) {
805 fbc
->no_fbc_reason
= "framebuffer stride not supported";
809 if (!pixel_format_is_valid(dev_priv
, cache
->fb
.format
->format
)) {
810 fbc
->no_fbc_reason
= "pixel format is invalid";
814 /* WaFbcExceedCdClockThreshold:hsw,bdw */
815 if ((IS_HASWELL(dev_priv
) || IS_BROADWELL(dev_priv
)) &&
816 cache
->crtc
.hsw_bdw_pixel_rate
>= dev_priv
->cdclk
.hw
.cdclk
* 95 / 100) {
817 fbc
->no_fbc_reason
= "pixel rate is too big";
821 /* It is possible for the required CFB size change without a
822 * crtc->disable + crtc->enable since it is possible to change the
823 * stride without triggering a full modeset. Since we try to
824 * over-allocate the CFB, there's a chance we may keep FBC enabled even
825 * if this happens, but if we exceed the current CFB size we'll have to
826 * disable FBC. Notice that it would be possible to disable FBC, wait
827 * for a frame, free the stolen node, then try to reenable FBC in case
828 * we didn't get any invalidate/deactivate calls, but this would require
829 * a lot of tracking just for a specific case. If we conclude it's an
830 * important case, we can implement it later. */
831 if (intel_fbc_calculate_cfb_size(dev_priv
, &fbc
->state_cache
) >
832 fbc
->compressed_fb
.size
* fbc
->threshold
) {
833 fbc
->no_fbc_reason
= "CFB requirements changed";
840 static bool intel_fbc_can_enable(struct drm_i915_private
*dev_priv
)
842 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
844 if (intel_vgpu_active(dev_priv
)) {
845 fbc
->no_fbc_reason
= "VGPU is active";
849 if (!i915
.enable_fbc
) {
850 fbc
->no_fbc_reason
= "disabled per module param or by default";
854 if (fbc
->underrun_detected
) {
855 fbc
->no_fbc_reason
= "underrun detected";
862 static void intel_fbc_get_reg_params(struct intel_crtc
*crtc
,
863 struct intel_fbc_reg_params
*params
)
865 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
866 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
867 struct intel_fbc_state_cache
*cache
= &fbc
->state_cache
;
869 /* Since all our fields are integer types, use memset here so the
870 * comparison function can rely on memcmp because the padding will be
872 memset(params
, 0, sizeof(*params
));
874 params
->vma
= cache
->vma
;
876 params
->crtc
.pipe
= crtc
->pipe
;
877 params
->crtc
.plane
= crtc
->plane
;
878 params
->crtc
.fence_y_offset
= get_crtc_fence_y_offset(crtc
);
880 params
->fb
.format
= cache
->fb
.format
;
881 params
->fb
.stride
= cache
->fb
.stride
;
883 params
->cfb_size
= intel_fbc_calculate_cfb_size(dev_priv
, cache
);
886 static bool intel_fbc_reg_params_equal(struct intel_fbc_reg_params
*params1
,
887 struct intel_fbc_reg_params
*params2
)
889 /* We can use this since intel_fbc_get_reg_params() does a memset. */
890 return memcmp(params1
, params2
, sizeof(*params1
)) == 0;
893 void intel_fbc_pre_update(struct intel_crtc
*crtc
,
894 struct intel_crtc_state
*crtc_state
,
895 struct intel_plane_state
*plane_state
)
897 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
898 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
900 if (!fbc_supported(dev_priv
))
903 mutex_lock(&fbc
->lock
);
905 if (!multiple_pipes_ok(crtc
, plane_state
)) {
906 fbc
->no_fbc_reason
= "more than one pipe active";
910 if (!fbc
->enabled
|| fbc
->crtc
!= crtc
)
913 intel_fbc_update_state_cache(crtc
, crtc_state
, plane_state
);
916 intel_fbc_deactivate(dev_priv
);
918 mutex_unlock(&fbc
->lock
);
921 static void __intel_fbc_post_update(struct intel_crtc
*crtc
)
923 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
924 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
925 struct intel_fbc_reg_params old_params
;
927 WARN_ON(!mutex_is_locked(&fbc
->lock
));
929 if (!fbc
->enabled
|| fbc
->crtc
!= crtc
)
932 if (!intel_fbc_can_activate(crtc
)) {
933 WARN_ON(fbc
->active
);
937 old_params
= fbc
->params
;
938 intel_fbc_get_reg_params(crtc
, &fbc
->params
);
940 /* If the scanout has not changed, don't modify the FBC settings.
941 * Note that we make the fundamental assumption that the fb->obj
942 * cannot be unpinned (and have its GTT offset and fence revoked)
943 * without first being decoupled from the scanout and FBC disabled.
946 intel_fbc_reg_params_equal(&old_params
, &fbc
->params
))
949 intel_fbc_deactivate(dev_priv
);
950 intel_fbc_schedule_activation(crtc
);
951 fbc
->no_fbc_reason
= "FBC enabled (active or scheduled)";
954 void intel_fbc_post_update(struct intel_crtc
*crtc
)
956 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
957 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
959 if (!fbc_supported(dev_priv
))
962 mutex_lock(&fbc
->lock
);
963 __intel_fbc_post_update(crtc
);
964 mutex_unlock(&fbc
->lock
);
967 static unsigned int intel_fbc_get_frontbuffer_bit(struct intel_fbc
*fbc
)
970 return to_intel_plane(fbc
->crtc
->base
.primary
)->frontbuffer_bit
;
972 return fbc
->possible_framebuffer_bits
;
975 void intel_fbc_invalidate(struct drm_i915_private
*dev_priv
,
976 unsigned int frontbuffer_bits
,
977 enum fb_op_origin origin
)
979 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
981 if (!fbc_supported(dev_priv
))
984 if (origin
== ORIGIN_GTT
|| origin
== ORIGIN_FLIP
)
987 mutex_lock(&fbc
->lock
);
989 fbc
->busy_bits
|= intel_fbc_get_frontbuffer_bit(fbc
) & frontbuffer_bits
;
991 if (fbc
->enabled
&& fbc
->busy_bits
)
992 intel_fbc_deactivate(dev_priv
);
994 mutex_unlock(&fbc
->lock
);
997 void intel_fbc_flush(struct drm_i915_private
*dev_priv
,
998 unsigned int frontbuffer_bits
, enum fb_op_origin origin
)
1000 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1002 if (!fbc_supported(dev_priv
))
1005 mutex_lock(&fbc
->lock
);
1007 fbc
->busy_bits
&= ~frontbuffer_bits
;
1009 if (origin
== ORIGIN_GTT
|| origin
== ORIGIN_FLIP
)
1012 if (!fbc
->busy_bits
&& fbc
->enabled
&&
1013 (frontbuffer_bits
& intel_fbc_get_frontbuffer_bit(fbc
))) {
1015 intel_fbc_recompress(dev_priv
);
1017 __intel_fbc_post_update(fbc
->crtc
);
1021 mutex_unlock(&fbc
->lock
);
1025 * intel_fbc_choose_crtc - select a CRTC to enable FBC on
1026 * @dev_priv: i915 device instance
1027 * @state: the atomic state structure
1029 * This function looks at the proposed state for CRTCs and planes, then chooses
1030 * which pipe is going to have FBC by setting intel_crtc_state->enable_fbc to
1033 * Later, intel_fbc_enable is going to look for state->enable_fbc and then maybe
1034 * enable FBC for the chosen CRTC. If it does, it will set dev_priv->fbc.crtc.
1036 void intel_fbc_choose_crtc(struct drm_i915_private
*dev_priv
,
1037 struct drm_atomic_state
*state
)
1039 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1040 struct drm_plane
*plane
;
1041 struct drm_plane_state
*plane_state
;
1042 bool crtc_chosen
= false;
1045 mutex_lock(&fbc
->lock
);
1047 /* Does this atomic commit involve the CRTC currently tied to FBC? */
1049 !drm_atomic_get_existing_crtc_state(state
, &fbc
->crtc
->base
))
1052 if (!intel_fbc_can_enable(dev_priv
))
1055 /* Simply choose the first CRTC that is compatible and has a visible
1056 * plane. We could go for fancier schemes such as checking the plane
1057 * size, but this would just affect the few platforms that don't tie FBC
1058 * to pipe or plane A. */
1059 for_each_new_plane_in_state(state
, plane
, plane_state
, i
) {
1060 struct intel_plane_state
*intel_plane_state
=
1061 to_intel_plane_state(plane_state
);
1062 struct intel_crtc_state
*intel_crtc_state
;
1063 struct intel_crtc
*crtc
= to_intel_crtc(plane_state
->crtc
);
1065 if (!intel_plane_state
->base
.visible
)
1068 if (fbc_on_pipe_a_only(dev_priv
) && crtc
->pipe
!= PIPE_A
)
1071 if (fbc_on_plane_a_only(dev_priv
) && crtc
->plane
!= PLANE_A
)
1074 intel_crtc_state
= to_intel_crtc_state(
1075 drm_atomic_get_existing_crtc_state(state
, &crtc
->base
));
1077 intel_crtc_state
->enable_fbc
= true;
1083 fbc
->no_fbc_reason
= "no suitable CRTC for FBC";
1086 mutex_unlock(&fbc
->lock
);
1090 * intel_fbc_enable: tries to enable FBC on the CRTC
1092 * @crtc_state: corresponding &drm_crtc_state for @crtc
1093 * @plane_state: corresponding &drm_plane_state for the primary plane of @crtc
1095 * This function checks if the given CRTC was chosen for FBC, then enables it if
1096 * possible. Notice that it doesn't activate FBC. It is valid to call
1097 * intel_fbc_enable multiple times for the same pipe without an
1098 * intel_fbc_disable in the middle, as long as it is deactivated.
1100 void intel_fbc_enable(struct intel_crtc
*crtc
,
1101 struct intel_crtc_state
*crtc_state
,
1102 struct intel_plane_state
*plane_state
)
1104 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
1105 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1107 if (!fbc_supported(dev_priv
))
1110 mutex_lock(&fbc
->lock
);
1113 WARN_ON(fbc
->crtc
== NULL
);
1114 if (fbc
->crtc
== crtc
) {
1115 WARN_ON(!crtc_state
->enable_fbc
);
1116 WARN_ON(fbc
->active
);
1121 if (!crtc_state
->enable_fbc
)
1124 WARN_ON(fbc
->active
);
1125 WARN_ON(fbc
->crtc
!= NULL
);
1127 intel_fbc_update_state_cache(crtc
, crtc_state
, plane_state
);
1128 if (intel_fbc_alloc_cfb(crtc
)) {
1129 fbc
->no_fbc_reason
= "not enough stolen memory";
1133 DRM_DEBUG_KMS("Enabling FBC on pipe %c\n", pipe_name(crtc
->pipe
));
1134 fbc
->no_fbc_reason
= "FBC enabled but not active yet\n";
1136 fbc
->enabled
= true;
1139 mutex_unlock(&fbc
->lock
);
1143 * __intel_fbc_disable - disable FBC
1144 * @dev_priv: i915 device instance
1146 * This is the low level function that actually disables FBC. Callers should
1147 * grab the FBC lock.
1149 static void __intel_fbc_disable(struct drm_i915_private
*dev_priv
)
1151 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1152 struct intel_crtc
*crtc
= fbc
->crtc
;
1154 WARN_ON(!mutex_is_locked(&fbc
->lock
));
1155 WARN_ON(!fbc
->enabled
);
1156 WARN_ON(fbc
->active
);
1157 WARN_ON(crtc
->active
);
1159 DRM_DEBUG_KMS("Disabling FBC on pipe %c\n", pipe_name(crtc
->pipe
));
1161 __intel_fbc_cleanup_cfb(dev_priv
);
1163 fbc
->enabled
= false;
1168 * intel_fbc_disable - disable FBC if it's associated with crtc
1171 * This function disables FBC if it's associated with the provided CRTC.
1173 void intel_fbc_disable(struct intel_crtc
*crtc
)
1175 struct drm_i915_private
*dev_priv
= to_i915(crtc
->base
.dev
);
1176 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1178 if (!fbc_supported(dev_priv
))
1181 mutex_lock(&fbc
->lock
);
1182 if (fbc
->crtc
== crtc
)
1183 __intel_fbc_disable(dev_priv
);
1184 mutex_unlock(&fbc
->lock
);
1186 cancel_work_sync(&fbc
->work
.work
);
1190 * intel_fbc_global_disable - globally disable FBC
1191 * @dev_priv: i915 device instance
1193 * This function disables FBC regardless of which CRTC is associated with it.
1195 void intel_fbc_global_disable(struct drm_i915_private
*dev_priv
)
1197 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1199 if (!fbc_supported(dev_priv
))
1202 mutex_lock(&fbc
->lock
);
1204 __intel_fbc_disable(dev_priv
);
1205 mutex_unlock(&fbc
->lock
);
1207 cancel_work_sync(&fbc
->work
.work
);
1210 static void intel_fbc_underrun_work_fn(struct work_struct
*work
)
1212 struct drm_i915_private
*dev_priv
=
1213 container_of(work
, struct drm_i915_private
, fbc
.underrun_work
);
1214 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1216 mutex_lock(&fbc
->lock
);
1218 /* Maybe we were scheduled twice. */
1219 if (fbc
->underrun_detected
)
1222 DRM_DEBUG_KMS("Disabling FBC due to FIFO underrun.\n");
1223 fbc
->underrun_detected
= true;
1225 intel_fbc_deactivate(dev_priv
);
1227 mutex_unlock(&fbc
->lock
);
1231 * intel_fbc_handle_fifo_underrun_irq - disable FBC when we get a FIFO underrun
1232 * @dev_priv: i915 device instance
1234 * Without FBC, most underruns are harmless and don't really cause too many
1235 * problems, except for an annoying message on dmesg. With FBC, underruns can
1236 * become black screens or even worse, especially when paired with bad
1237 * watermarks. So in order for us to be on the safe side, completely disable FBC
1238 * in case we ever detect a FIFO underrun on any pipe. An underrun on any pipe
1239 * already suggests that watermarks may be bad, so try to be as safe as
1242 * This function is called from the IRQ handler.
1244 void intel_fbc_handle_fifo_underrun_irq(struct drm_i915_private
*dev_priv
)
1246 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1248 if (!fbc_supported(dev_priv
))
1251 /* There's no guarantee that underrun_detected won't be set to true
1252 * right after this check and before the work is scheduled, but that's
1253 * not a problem since we'll check it again under the work function
1254 * while FBC is locked. This check here is just to prevent us from
1255 * unnecessarily scheduling the work, and it relies on the fact that we
1256 * never switch underrun_detect back to false after it's true. */
1257 if (READ_ONCE(fbc
->underrun_detected
))
1260 schedule_work(&fbc
->underrun_work
);
1264 * intel_fbc_init_pipe_state - initialize FBC's CRTC visibility tracking
1265 * @dev_priv: i915 device instance
1267 * The FBC code needs to track CRTC visibility since the older platforms can't
1268 * have FBC enabled while multiple pipes are used. This function does the
1269 * initial setup at driver load to make sure FBC is matching the real hardware.
1271 void intel_fbc_init_pipe_state(struct drm_i915_private
*dev_priv
)
1273 struct intel_crtc
*crtc
;
1275 /* Don't even bother tracking anything if we don't need. */
1276 if (!no_fbc_on_multiple_pipes(dev_priv
))
1279 for_each_intel_crtc(&dev_priv
->drm
, crtc
)
1280 if (intel_crtc_active(crtc
) &&
1281 crtc
->base
.primary
->state
->visible
)
1282 dev_priv
->fbc
.visible_pipes_mask
|= (1 << crtc
->pipe
);
1286 * The DDX driver changes its behavior depending on the value it reads from
1287 * i915.enable_fbc, so sanitize it by translating the default value into either
1288 * 0 or 1 in order to allow it to know what's going on.
1290 * Notice that this is done at driver initialization and we still allow user
1291 * space to change the value during runtime without sanitizing it again. IGT
1292 * relies on being able to change i915.enable_fbc at runtime.
1294 static int intel_sanitize_fbc_option(struct drm_i915_private
*dev_priv
)
1296 if (i915
.enable_fbc
>= 0)
1297 return !!i915
.enable_fbc
;
1299 if (!HAS_FBC(dev_priv
))
1302 if (IS_BROADWELL(dev_priv
) || INTEL_GEN(dev_priv
) >= 9)
1308 static bool need_fbc_vtd_wa(struct drm_i915_private
*dev_priv
)
1310 /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
1311 if (intel_vtd_active() &&
1312 (IS_SKYLAKE(dev_priv
) || IS_BROXTON(dev_priv
))) {
1313 DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
1321 * intel_fbc_init - Initialize FBC
1322 * @dev_priv: the i915 device
1324 * This function might be called during PM init process.
1326 void intel_fbc_init(struct drm_i915_private
*dev_priv
)
1328 struct intel_fbc
*fbc
= &dev_priv
->fbc
;
1331 INIT_WORK(&fbc
->work
.work
, intel_fbc_work_fn
);
1332 INIT_WORK(&fbc
->underrun_work
, intel_fbc_underrun_work_fn
);
1333 mutex_init(&fbc
->lock
);
1334 fbc
->enabled
= false;
1335 fbc
->active
= false;
1336 fbc
->work
.scheduled
= false;
1338 if (need_fbc_vtd_wa(dev_priv
))
1339 mkwrite_device_info(dev_priv
)->has_fbc
= false;
1341 i915
.enable_fbc
= intel_sanitize_fbc_option(dev_priv
);
1342 DRM_DEBUG_KMS("Sanitized enable_fbc value: %d\n", i915
.enable_fbc
);
1344 if (!HAS_FBC(dev_priv
)) {
1345 fbc
->no_fbc_reason
= "unsupported by this chipset";
1349 for_each_pipe(dev_priv
, pipe
) {
1350 fbc
->possible_framebuffer_bits
|=
1351 INTEL_FRONTBUFFER_PRIMARY(pipe
);
1353 if (fbc_on_pipe_a_only(dev_priv
))
1357 /* This value was pulled out of someone's hat */
1358 if (INTEL_GEN(dev_priv
) <= 4 && !IS_GM45(dev_priv
))
1359 I915_WRITE(FBC_CONTROL
, 500 << FBC_CTL_INTERVAL_SHIFT
);
1361 /* We still don't have any sort of hardware state readout for FBC, so
1362 * deactivate it in case the BIOS activated it to make sure software
1363 * matches the hardware state. */
1364 if (intel_fbc_hw_is_active(dev_priv
))
1365 intel_fbc_hw_deactivate(dev_priv
);