1 // SPDX-License-Identifier: GPL-2.0-only
2 /**************************************************************************
3 * Copyright (c) 2007, Intel Corporation.
6 * Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
9 **************************************************************************/
11 #include <drm/drm_vblank.h>
13 #include "mdfld_output.h"
16 #include "psb_intel_reg.h"
25 psb_pipestat(int pipe
)
37 mid_pipe_event(int pipe
)
40 return _PSB_PIPEA_EVENT_FLAG
;
42 return _MDFLD_PIPEB_EVENT_FLAG
;
44 return _MDFLD_PIPEC_EVENT_FLAG
;
49 mid_pipe_vsync(int pipe
)
52 return _PSB_VSYNC_PIPEA_FLAG
;
54 return _PSB_VSYNC_PIPEB_FLAG
;
56 return _MDFLD_PIPEC_VBLANK_FLAG
;
61 mid_pipeconf(int pipe
)
73 psb_enable_pipestat(struct drm_psb_private
*dev_priv
, int pipe
, u32 mask
)
75 if ((dev_priv
->pipestat
[pipe
] & mask
) != mask
) {
76 u32 reg
= psb_pipestat(pipe
);
77 dev_priv
->pipestat
[pipe
] |= mask
;
78 /* Enable the interrupt, clear any pending status */
79 if (gma_power_begin(dev_priv
->dev
, false)) {
80 u32 writeVal
= PSB_RVDC32(reg
);
81 writeVal
|= (mask
| (mask
>> 16));
82 PSB_WVDC32(writeVal
, reg
);
83 (void) PSB_RVDC32(reg
);
84 gma_power_end(dev_priv
->dev
);
90 psb_disable_pipestat(struct drm_psb_private
*dev_priv
, int pipe
, u32 mask
)
92 if ((dev_priv
->pipestat
[pipe
] & mask
) != 0) {
93 u32 reg
= psb_pipestat(pipe
);
94 dev_priv
->pipestat
[pipe
] &= ~mask
;
95 if (gma_power_begin(dev_priv
->dev
, false)) {
96 u32 writeVal
= PSB_RVDC32(reg
);
98 PSB_WVDC32(writeVal
, reg
);
99 (void) PSB_RVDC32(reg
);
100 gma_power_end(dev_priv
->dev
);
105 static void mid_enable_pipe_event(struct drm_psb_private
*dev_priv
, int pipe
)
107 if (gma_power_begin(dev_priv
->dev
, false)) {
108 u32 pipe_event
= mid_pipe_event(pipe
);
109 dev_priv
->vdc_irq_mask
|= pipe_event
;
110 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
111 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
112 gma_power_end(dev_priv
->dev
);
116 static void mid_disable_pipe_event(struct drm_psb_private
*dev_priv
, int pipe
)
118 if (dev_priv
->pipestat
[pipe
] == 0) {
119 if (gma_power_begin(dev_priv
->dev
, false)) {
120 u32 pipe_event
= mid_pipe_event(pipe
);
121 dev_priv
->vdc_irq_mask
&= ~pipe_event
;
122 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
123 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
124 gma_power_end(dev_priv
->dev
);
130 * Display controller interrupt handler for pipe event.
133 static void mid_pipe_event_handler(struct drm_device
*dev
, int pipe
)
135 struct drm_psb_private
*dev_priv
=
136 (struct drm_psb_private
*) dev
->dev_private
;
138 uint32_t pipe_stat_val
= 0;
139 uint32_t pipe_stat_reg
= psb_pipestat(pipe
);
140 uint32_t pipe_enable
= dev_priv
->pipestat
[pipe
];
141 uint32_t pipe_status
= dev_priv
->pipestat
[pipe
] >> 16;
145 spin_lock(&dev_priv
->irqmask_lock
);
147 pipe_stat_val
= PSB_RVDC32(pipe_stat_reg
);
148 pipe_stat_val
&= pipe_enable
| pipe_status
;
149 pipe_stat_val
&= pipe_stat_val
>> 16;
151 spin_unlock(&dev_priv
->irqmask_lock
);
153 /* Clear the 2nd level interrupt status bits
154 * Sometimes the bits are very sticky so we repeat until they unstick */
155 for (i
= 0; i
< 0xffff; i
++) {
156 PSB_WVDC32(PSB_RVDC32(pipe_stat_reg
), pipe_stat_reg
);
157 pipe_clear
= PSB_RVDC32(pipe_stat_reg
) & pipe_status
;
165 "%s, can't clear status bits for pipe %d, its value = 0x%x.\n",
166 __func__
, pipe
, PSB_RVDC32(pipe_stat_reg
));
168 if (pipe_stat_val
& PIPE_VBLANK_STATUS
||
169 (IS_MFLD(dev
) && pipe_stat_val
& PIPE_TE_STATUS
)) {
170 struct drm_crtc
*crtc
= drm_crtc_from_index(dev
, pipe
);
171 struct gma_crtc
*gma_crtc
= to_gma_crtc(crtc
);
174 drm_handle_vblank(dev
, pipe
);
176 spin_lock_irqsave(&dev
->event_lock
, flags
);
177 if (gma_crtc
->page_flip_event
) {
178 drm_crtc_send_vblank_event(crtc
,
179 gma_crtc
->page_flip_event
);
180 gma_crtc
->page_flip_event
= NULL
;
181 drm_crtc_vblank_put(crtc
);
183 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
188 * Display controller interrupt handler.
190 static void psb_vdc_interrupt(struct drm_device
*dev
, uint32_t vdc_stat
)
192 if (vdc_stat
& _PSB_IRQ_ASLE
)
193 psb_intel_opregion_asle_intr(dev
);
195 if (vdc_stat
& _PSB_VSYNC_PIPEA_FLAG
)
196 mid_pipe_event_handler(dev
, 0);
198 if (vdc_stat
& _PSB_VSYNC_PIPEB_FLAG
)
199 mid_pipe_event_handler(dev
, 1);
203 * SGX interrupt handler
205 static void psb_sgx_interrupt(struct drm_device
*dev
, u32 stat_1
, u32 stat_2
)
207 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
210 if (stat_1
& _PSB_CE_TWOD_COMPLETE
)
211 val
= PSB_RSGX32(PSB_CR_2D_BLIT_STATUS
);
213 if (stat_2
& _PSB_CE2_BIF_REQUESTER_FAULT
) {
214 val
= PSB_RSGX32(PSB_CR_BIF_INT_STAT
);
215 addr
= PSB_RSGX32(PSB_CR_BIF_FAULT
);
217 if (val
& _PSB_CBI_STAT_PF_N_RW
)
218 DRM_ERROR("SGX MMU page fault:");
220 DRM_ERROR("SGX MMU read / write protection fault:");
222 if (val
& _PSB_CBI_STAT_FAULT_CACHE
)
223 DRM_ERROR("\tCache requestor");
224 if (val
& _PSB_CBI_STAT_FAULT_TA
)
225 DRM_ERROR("\tTA requestor");
226 if (val
& _PSB_CBI_STAT_FAULT_VDM
)
227 DRM_ERROR("\tVDM requestor");
228 if (val
& _PSB_CBI_STAT_FAULT_2D
)
229 DRM_ERROR("\t2D requestor");
230 if (val
& _PSB_CBI_STAT_FAULT_PBE
)
231 DRM_ERROR("\tPBE requestor");
232 if (val
& _PSB_CBI_STAT_FAULT_TSP
)
233 DRM_ERROR("\tTSP requestor");
234 if (val
& _PSB_CBI_STAT_FAULT_ISP
)
235 DRM_ERROR("\tISP requestor");
236 if (val
& _PSB_CBI_STAT_FAULT_USSEPDS
)
237 DRM_ERROR("\tUSSEPDS requestor");
238 if (val
& _PSB_CBI_STAT_FAULT_HOST
)
239 DRM_ERROR("\tHost requestor");
241 DRM_ERROR("\tMMU failing address is 0x%08x.\n",
247 PSB_WSGX32(stat_1
, PSB_CR_EVENT_HOST_CLEAR
);
248 PSB_WSGX32(stat_2
, PSB_CR_EVENT_HOST_CLEAR2
);
249 PSB_RSGX32(PSB_CR_EVENT_HOST_CLEAR2
);
252 irqreturn_t
psb_irq_handler(int irq
, void *arg
)
254 struct drm_device
*dev
= arg
;
255 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
256 uint32_t vdc_stat
, dsp_int
= 0, sgx_int
= 0, hotplug_int
= 0;
257 u32 sgx_stat_1
, sgx_stat_2
;
260 spin_lock(&dev_priv
->irqmask_lock
);
262 vdc_stat
= PSB_RVDC32(PSB_INT_IDENTITY_R
);
264 if (vdc_stat
& (_PSB_PIPE_EVENT_FLAG
|_PSB_IRQ_ASLE
))
267 /* FIXME: Handle Medfield
268 if (vdc_stat & _MDFLD_DISP_ALL_IRQ_FLAG)
272 if (vdc_stat
& _PSB_IRQ_SGX_FLAG
)
274 if (vdc_stat
& _PSB_IRQ_DISP_HOTSYNC
)
277 vdc_stat
&= dev_priv
->vdc_irq_mask
;
278 spin_unlock(&dev_priv
->irqmask_lock
);
280 if (dsp_int
&& gma_power_is_on(dev
)) {
281 psb_vdc_interrupt(dev
, vdc_stat
);
286 sgx_stat_1
= PSB_RSGX32(PSB_CR_EVENT_STATUS
);
287 sgx_stat_2
= PSB_RSGX32(PSB_CR_EVENT_STATUS2
);
288 psb_sgx_interrupt(dev
, sgx_stat_1
, sgx_stat_2
);
292 /* Note: this bit has other meanings on some devices, so we will
293 need to address that later if it ever matters */
294 if (hotplug_int
&& dev_priv
->ops
->hotplug
) {
295 handled
= dev_priv
->ops
->hotplug(dev
);
296 REG_WRITE(PORT_HOTPLUG_STAT
, REG_READ(PORT_HOTPLUG_STAT
));
299 PSB_WVDC32(vdc_stat
, PSB_INT_IDENTITY_R
);
300 (void) PSB_RVDC32(PSB_INT_IDENTITY_R
);
309 void psb_irq_preinstall(struct drm_device
*dev
)
311 struct drm_psb_private
*dev_priv
=
312 (struct drm_psb_private
*) dev
->dev_private
;
313 unsigned long irqflags
;
315 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
317 if (gma_power_is_on(dev
)) {
318 PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM
);
319 PSB_WVDC32(0x00000000, PSB_INT_MASK_R
);
320 PSB_WVDC32(0x00000000, PSB_INT_ENABLE_R
);
321 PSB_WSGX32(0x00000000, PSB_CR_EVENT_HOST_ENABLE
);
322 PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE
);
324 if (dev
->vblank
[0].enabled
)
325 dev_priv
->vdc_irq_mask
|= _PSB_VSYNC_PIPEA_FLAG
;
326 if (dev
->vblank
[1].enabled
)
327 dev_priv
->vdc_irq_mask
|= _PSB_VSYNC_PIPEB_FLAG
;
329 /* FIXME: Handle Medfield irq mask
330 if (dev->vblank[1].enabled)
331 dev_priv->vdc_irq_mask |= _MDFLD_PIPEB_EVENT_FLAG;
332 if (dev->vblank[2].enabled)
333 dev_priv->vdc_irq_mask |= _MDFLD_PIPEC_EVENT_FLAG;
336 /* Revisit this area - want per device masks ? */
337 if (dev_priv
->ops
->hotplug
)
338 dev_priv
->vdc_irq_mask
|= _PSB_IRQ_DISP_HOTSYNC
;
339 dev_priv
->vdc_irq_mask
|= _PSB_IRQ_ASLE
| _PSB_IRQ_SGX_FLAG
;
341 /* This register is safe even if display island is off */
342 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
343 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
346 int psb_irq_postinstall(struct drm_device
*dev
)
348 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
349 unsigned long irqflags
;
352 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
354 /* Enable 2D and MMU fault interrupts */
355 PSB_WSGX32(_PSB_CE2_BIF_REQUESTER_FAULT
, PSB_CR_EVENT_HOST_ENABLE2
);
356 PSB_WSGX32(_PSB_CE_TWOD_COMPLETE
, PSB_CR_EVENT_HOST_ENABLE
);
357 PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE
); /* Post */
359 /* This register is safe even if display island is off */
360 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
361 PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM
);
363 for (i
= 0; i
< dev
->num_crtcs
; ++i
) {
364 if (dev
->vblank
[i
].enabled
)
365 psb_enable_pipestat(dev_priv
, i
, PIPE_VBLANK_INTERRUPT_ENABLE
);
367 psb_disable_pipestat(dev_priv
, i
, PIPE_VBLANK_INTERRUPT_ENABLE
);
370 if (dev_priv
->ops
->hotplug_enable
)
371 dev_priv
->ops
->hotplug_enable(dev
, true);
373 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
377 void psb_irq_uninstall(struct drm_device
*dev
)
379 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
380 unsigned long irqflags
;
383 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
385 if (dev_priv
->ops
->hotplug_enable
)
386 dev_priv
->ops
->hotplug_enable(dev
, false);
388 PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM
);
390 for (i
= 0; i
< dev
->num_crtcs
; ++i
) {
391 if (dev
->vblank
[i
].enabled
)
392 psb_disable_pipestat(dev_priv
, i
, PIPE_VBLANK_INTERRUPT_ENABLE
);
395 dev_priv
->vdc_irq_mask
&= _PSB_IRQ_SGX_FLAG
|
396 _PSB_IRQ_MSVDX_FLAG
|
399 /* These two registers are safe even if display island is off */
400 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
401 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
405 /* This register is safe even if display island is off */
406 PSB_WVDC32(PSB_RVDC32(PSB_INT_IDENTITY_R
), PSB_INT_IDENTITY_R
);
407 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
410 void psb_irq_turn_on_dpst(struct drm_device
*dev
)
412 struct drm_psb_private
*dev_priv
=
413 (struct drm_psb_private
*) dev
->dev_private
;
417 if (gma_power_begin(dev
, false)) {
418 PSB_WVDC32(1 << 31, HISTOGRAM_LOGIC_CONTROL
);
419 hist_reg
= PSB_RVDC32(HISTOGRAM_LOGIC_CONTROL
);
420 PSB_WVDC32(1 << 31, HISTOGRAM_INT_CONTROL
);
421 hist_reg
= PSB_RVDC32(HISTOGRAM_INT_CONTROL
);
423 PSB_WVDC32(0x80010100, PWM_CONTROL_LOGIC
);
424 pwm_reg
= PSB_RVDC32(PWM_CONTROL_LOGIC
);
425 PSB_WVDC32(pwm_reg
| PWM_PHASEIN_ENABLE
426 | PWM_PHASEIN_INT_ENABLE
,
428 pwm_reg
= PSB_RVDC32(PWM_CONTROL_LOGIC
);
430 psb_enable_pipestat(dev_priv
, 0, PIPE_DPST_EVENT_ENABLE
);
432 hist_reg
= PSB_RVDC32(HISTOGRAM_INT_CONTROL
);
433 PSB_WVDC32(hist_reg
| HISTOGRAM_INT_CTRL_CLEAR
,
434 HISTOGRAM_INT_CONTROL
);
435 pwm_reg
= PSB_RVDC32(PWM_CONTROL_LOGIC
);
436 PSB_WVDC32(pwm_reg
| 0x80010100 | PWM_PHASEIN_ENABLE
,
443 int psb_irq_enable_dpst(struct drm_device
*dev
)
445 struct drm_psb_private
*dev_priv
=
446 (struct drm_psb_private
*) dev
->dev_private
;
447 unsigned long irqflags
;
449 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
452 mid_enable_pipe_event(dev_priv
, 0);
453 psb_irq_turn_on_dpst(dev
);
455 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
459 void psb_irq_turn_off_dpst(struct drm_device
*dev
)
461 struct drm_psb_private
*dev_priv
=
462 (struct drm_psb_private
*) dev
->dev_private
;
465 if (gma_power_begin(dev
, false)) {
466 PSB_WVDC32(0x00000000, HISTOGRAM_INT_CONTROL
);
467 PSB_RVDC32(HISTOGRAM_INT_CONTROL
);
469 psb_disable_pipestat(dev_priv
, 0, PIPE_DPST_EVENT_ENABLE
);
471 pwm_reg
= PSB_RVDC32(PWM_CONTROL_LOGIC
);
472 PSB_WVDC32(pwm_reg
& ~PWM_PHASEIN_INT_ENABLE
,
474 pwm_reg
= PSB_RVDC32(PWM_CONTROL_LOGIC
);
480 int psb_irq_disable_dpst(struct drm_device
*dev
)
482 struct drm_psb_private
*dev_priv
=
483 (struct drm_psb_private
*) dev
->dev_private
;
484 unsigned long irqflags
;
486 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
488 mid_disable_pipe_event(dev_priv
, 0);
489 psb_irq_turn_off_dpst(dev
);
491 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
497 * It is used to enable VBLANK interrupt
499 int psb_enable_vblank(struct drm_crtc
*crtc
)
501 struct drm_device
*dev
= crtc
->dev
;
502 unsigned int pipe
= crtc
->index
;
503 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
504 unsigned long irqflags
;
505 uint32_t reg_val
= 0;
506 uint32_t pipeconf_reg
= mid_pipeconf(pipe
);
508 /* Medfield is different - we should perhaps extract out vblank
509 and blacklight etc ops */
511 return mdfld_enable_te(dev
, pipe
);
513 if (gma_power_begin(dev
, false)) {
514 reg_val
= REG_READ(pipeconf_reg
);
518 if (!(reg_val
& PIPEACONF_ENABLE
))
521 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
524 dev_priv
->vdc_irq_mask
|= _PSB_VSYNC_PIPEA_FLAG
;
526 dev_priv
->vdc_irq_mask
|= _PSB_VSYNC_PIPEB_FLAG
;
528 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
529 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
530 psb_enable_pipestat(dev_priv
, pipe
, PIPE_VBLANK_INTERRUPT_ENABLE
);
532 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
538 * It is used to disable VBLANK interrupt
540 void psb_disable_vblank(struct drm_crtc
*crtc
)
542 struct drm_device
*dev
= crtc
->dev
;
543 unsigned int pipe
= crtc
->index
;
544 struct drm_psb_private
*dev_priv
= dev
->dev_private
;
545 unsigned long irqflags
;
548 mdfld_disable_te(dev
, pipe
);
549 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
552 dev_priv
->vdc_irq_mask
&= ~_PSB_VSYNC_PIPEA_FLAG
;
554 dev_priv
->vdc_irq_mask
&= ~_PSB_VSYNC_PIPEB_FLAG
;
556 PSB_WVDC32(~dev_priv
->vdc_irq_mask
, PSB_INT_MASK_R
);
557 PSB_WVDC32(dev_priv
->vdc_irq_mask
, PSB_INT_ENABLE_R
);
558 psb_disable_pipestat(dev_priv
, pipe
, PIPE_VBLANK_INTERRUPT_ENABLE
);
560 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
564 * It is used to enable TE interrupt
566 int mdfld_enable_te(struct drm_device
*dev
, int pipe
)
568 struct drm_psb_private
*dev_priv
=
569 (struct drm_psb_private
*) dev
->dev_private
;
570 unsigned long irqflags
;
571 uint32_t reg_val
= 0;
572 uint32_t pipeconf_reg
= mid_pipeconf(pipe
);
574 if (gma_power_begin(dev
, false)) {
575 reg_val
= REG_READ(pipeconf_reg
);
579 if (!(reg_val
& PIPEACONF_ENABLE
))
582 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
584 mid_enable_pipe_event(dev_priv
, pipe
);
585 psb_enable_pipestat(dev_priv
, pipe
, PIPE_TE_ENABLE
);
587 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
593 * It is used to disable TE interrupt
595 void mdfld_disable_te(struct drm_device
*dev
, int pipe
)
597 struct drm_psb_private
*dev_priv
=
598 (struct drm_psb_private
*) dev
->dev_private
;
599 unsigned long irqflags
;
601 if (!dev_priv
->dsr_enable
)
604 spin_lock_irqsave(&dev_priv
->irqmask_lock
, irqflags
);
606 mid_disable_pipe_event(dev_priv
, pipe
);
607 psb_disable_pipestat(dev_priv
, pipe
, PIPE_TE_ENABLE
);
609 spin_unlock_irqrestore(&dev_priv
->irqmask_lock
, irqflags
);
612 /* Called from drm generic code, passed a 'crtc', which
613 * we use as a pipe index
615 u32
psb_get_vblank_counter(struct drm_crtc
*crtc
)
617 struct drm_device
*dev
= crtc
->dev
;
618 unsigned int pipe
= crtc
->index
;
619 uint32_t high_frame
= PIPEAFRAMEHIGH
;
620 uint32_t low_frame
= PIPEAFRAMEPIXEL
;
621 uint32_t pipeconf_reg
= PIPEACONF
;
622 uint32_t reg_val
= 0;
623 uint32_t high1
= 0, high2
= 0, low
= 0, count
= 0;
629 high_frame
= PIPEBFRAMEHIGH
;
630 low_frame
= PIPEBFRAMEPIXEL
;
631 pipeconf_reg
= PIPEBCONF
;
634 high_frame
= PIPECFRAMEHIGH
;
635 low_frame
= PIPECFRAMEPIXEL
;
636 pipeconf_reg
= PIPECCONF
;
639 dev_err(dev
->dev
, "%s, invalid pipe.\n", __func__
);
643 if (!gma_power_begin(dev
, false))
646 reg_val
= REG_READ(pipeconf_reg
);
648 if (!(reg_val
& PIPEACONF_ENABLE
)) {
649 dev_err(dev
->dev
, "trying to get vblank count for disabled pipe %u\n",
651 goto psb_get_vblank_counter_exit
;
655 * High & low register fields aren't synchronized, so make sure
656 * we get a low value that's stable across two reads of the high
660 high1
= ((REG_READ(high_frame
) & PIPE_FRAME_HIGH_MASK
) >>
661 PIPE_FRAME_HIGH_SHIFT
);
662 low
= ((REG_READ(low_frame
) & PIPE_FRAME_LOW_MASK
) >>
663 PIPE_FRAME_LOW_SHIFT
);
664 high2
= ((REG_READ(high_frame
) & PIPE_FRAME_HIGH_MASK
) >>
665 PIPE_FRAME_HIGH_SHIFT
);
666 } while (high1
!= high2
);
668 count
= (high1
<< 8) | low
;
670 psb_get_vblank_counter_exit
: