aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_irq.c
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2014-05-08 10:41:51 -0400
committerDaniel Vetter <daniel.vetter@ffwll.ch>2014-05-21 05:31:06 -0400
commitf5752b38970990fa1495839751aed64bd178b9e0 (patch)
tree944485caa11b7c3a1c6d4faf6a715cad798512ee /drivers/gpu/drm/drm_irq.c
parent8edffbb933619d568ea98edd3b55ec7c30df9274 (diff)
drm/irq: kerneldoc polish
- Integrate into the drm DocBook - Disable kerneldoc for functions not exported to drivers. - Properly document the new drm_vblank_on|off and add cautious comments explaining when drm_vblank_pre|post_modesets shouldn't be used. - General polish and OCD. v2: Polish as suggested by Thierry. Cc: Thierry Reding <thierry.reding@gmail.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
-rw-r--r--drivers/gpu/drm/drm_irq.c165
1 files changed, 117 insertions, 48 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index dd786d84daab..f3dafccca456 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1,6 +1,5 @@
1/** 1/*
2 * \file drm_irq.c 2 * drm_irq.c IRQ and vblank support
3 * IRQ support
4 * 3 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com> 4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com> 5 * \author Gareth Hughes <gareth@valinux.com>
@@ -156,6 +155,12 @@ static void vblank_disable_fn(unsigned long arg)
156 spin_unlock_irqrestore(&dev->vbl_lock, irqflags); 155 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
157} 156}
158 157
158/**
159 * drm_vblank_cleanup - cleanup vblank support
160 * @dev: DRM device
161 *
162 * This function cleans up any resources allocated in drm_vblank_init.
163 */
159void drm_vblank_cleanup(struct drm_device *dev) 164void drm_vblank_cleanup(struct drm_device *dev)
160{ 165{
161 int crtc; 166 int crtc;
@@ -175,6 +180,16 @@ void drm_vblank_cleanup(struct drm_device *dev)
175} 180}
176EXPORT_SYMBOL(drm_vblank_cleanup); 181EXPORT_SYMBOL(drm_vblank_cleanup);
177 182
183/**
184 * drm_vblank_init - initialize vblank support
185 * @dev: drm_device
186 * @num_crtcs: number of crtcs supported by @dev
187 *
188 * This function initializes vblank support for @num_crtcs display pipelines.
189 *
190 * Returns:
191 * Zero on success or a negative error code on failure.
192 */
178int drm_vblank_init(struct drm_device *dev, int num_crtcs) 193int drm_vblank_init(struct drm_device *dev, int num_crtcs)
179{ 194{
180 int i, ret = -ENOMEM; 195 int i, ret = -ENOMEM;
@@ -238,13 +253,21 @@ static void drm_irq_vgaarb_nokms(void *cookie, bool state)
238} 253}
239 254
240/** 255/**
241 * Install IRQ handler. 256 * drm_irq_install - install IRQ handler
242 * 257 * @dev: DRM device
243 * \param dev DRM device. 258 * @irq: IRQ number to install the handler for
244 * 259 *
245 * Initializes the IRQ related data. Installs the handler, calling the driver 260 * Initializes the IRQ related data. Installs the handler, calling the driver
246 * \c irq_preinstall() and \c irq_postinstall() functions 261 * irq_preinstall() and irq_postinstall() functions before and after the
247 * before and after the installation. 262 * installation.
263 *
264 * This is the simplified helper interface provided for drivers with no special
265 * needs. Drivers which need to install interrupt handlers for multiple
266 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
267 * that vblank interrupts are available.
268 *
269 * Returns:
270 * Zero on success or a negative error code on failure.
248 */ 271 */
249int drm_irq_install(struct drm_device *dev, int irq) 272int drm_irq_install(struct drm_device *dev, int irq)
250{ 273{
@@ -304,11 +327,20 @@ int drm_irq_install(struct drm_device *dev, int irq)
304EXPORT_SYMBOL(drm_irq_install); 327EXPORT_SYMBOL(drm_irq_install);
305 328
306/** 329/**
307 * Uninstall the IRQ handler. 330 * drm_irq_uninstall - uninstall the IRQ handler
331 * @dev: DRM device
332 *
333 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
334 * This should only be called by drivers which used drm_irq_install() to set up
335 * their interrupt handler. Other drivers must only reset
336 * drm_device->irq_enabled to false.
308 * 337 *
309 * \param dev DRM device. 338 * Note that for kernel modesetting drivers it is a bug if this function fails.
339 * The sanity checks are only to catch buggy user modesetting drivers which call
340 * the same function through an ioctl.
310 * 341 *
311 * Calls the driver's \c irq_uninstall() function, and stops the irq. 342 * Returns:
343 * Zero on success or a negative error code on failure.
312 */ 344 */
313int drm_irq_uninstall(struct drm_device *dev) 345int drm_irq_uninstall(struct drm_device *dev)
314{ 346{
@@ -353,7 +385,7 @@ int drm_irq_uninstall(struct drm_device *dev)
353} 385}
354EXPORT_SYMBOL(drm_irq_uninstall); 386EXPORT_SYMBOL(drm_irq_uninstall);
355 387
356/** 388/*
357 * IRQ control ioctl. 389 * IRQ control ioctl.
358 * 390 *
359 * \param inode device inode. 391 * \param inode device inode.
@@ -406,15 +438,14 @@ int drm_control(struct drm_device *dev, void *data,
406} 438}
407 439
408/** 440/**
409 * drm_calc_timestamping_constants - Calculate vblank timestamp constants 441 * drm_calc_timestamping_constants - calculate vblank timestamp constants
410 * 442 * @crtc: drm_crtc whose timestamp constants should be updated.
411 * @crtc drm_crtc whose timestamp constants should be updated. 443 * @mode: display mode containing the scanout timings
412 * @mode display mode containing the scanout timings
413 * 444 *
414 * Calculate and store various constants which are later 445 * Calculate and store various constants which are later
415 * needed by vblank and swap-completion timestamping, e.g, 446 * needed by vblank and swap-completion timestamping, e.g,
416 * by drm_calc_vbltimestamp_from_scanoutpos(). They are 447 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
417 * derived from crtc's true scanout timing, so they take 448 * derived from CRTC's true scanout timing, so they take
418 * things like panel scaling or other adjustments into account. 449 * things like panel scaling or other adjustments into account.
419 */ 450 */
420void drm_calc_timestamping_constants(struct drm_crtc *crtc, 451void drm_calc_timestamping_constants(struct drm_crtc *crtc,
@@ -459,11 +490,22 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc,
459EXPORT_SYMBOL(drm_calc_timestamping_constants); 490EXPORT_SYMBOL(drm_calc_timestamping_constants);
460 491
461/** 492/**
462 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms 493 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
463 * drivers. Implements calculation of exact vblank timestamps from 494 * @dev: DRM device
464 * given drm_display_mode timings and current video scanout position 495 * @crtc: Which CRTC's vblank timestamp to retrieve
465 * of a crtc. This can be called from within get_vblank_timestamp() 496 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
466 * implementation of a kms driver to implement the actual timestamping. 497 * On return contains true maximum error of timestamp
498 * @vblank_time: Pointer to struct timeval which should receive the timestamp
499 * @flags: Flags to pass to driver:
500 * 0 = Default,
501 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
502 * @refcrtc: CRTC which defines scanout timing
503 * @mode: mode which defines the scanout timings
504 *
505 * Implements calculation of exact vblank timestamps from given drm_display_mode
506 * timings and current video scanout position of a CRTC. This can be called from
507 * within get_vblank_timestamp() implementation of a kms driver to implement the
508 * actual timestamping.
467 * 509 *
468 * Should return timestamps conforming to the OML_sync_control OpenML 510 * Should return timestamps conforming to the OML_sync_control OpenML
469 * extension specification. The timestamp corresponds to the end of 511 * extension specification. The timestamp corresponds to the end of
@@ -478,21 +520,11 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants);
478 * returns as no operation if a doublescan or interlaced video mode is 520 * returns as no operation if a doublescan or interlaced video mode is
479 * active. Higher level code is expected to handle this. 521 * active. Higher level code is expected to handle this.
480 * 522 *
481 * @dev: DRM device. 523 * Returns:
482 * @crtc: Which crtc's vblank timestamp to retrieve. 524 * Negative value on error, failure or if not supported in current
483 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
484 * On return contains true maximum error of timestamp.
485 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
486 * @flags: Flags to pass to driver:
487 * 0 = Default.
488 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
489 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
490 * @mode: mode which defines the scanout timings
491 *
492 * Returns negative value on error, failure or if not supported in current
493 * video mode: 525 * video mode:
494 * 526 *
495 * -EINVAL - Invalid crtc. 527 * -EINVAL - Invalid CRTC.
496 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset. 528 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
497 * -ENOTSUPP - Function not supported in current display mode. 529 * -ENOTSUPP - Function not supported in current display mode.
498 * -EIO - Failed, e.g., due to failed scanout position query. 530 * -EIO - Failed, e.g., due to failed scanout position query.
@@ -641,23 +673,23 @@ static struct timeval get_drm_timestamp(void)
641 673
642/** 674/**
643 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent 675 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
644 * vblank interval. 676 * vblank interval
645 *
646 * @dev: DRM device 677 * @dev: DRM device
647 * @crtc: which crtc's vblank timestamp to retrieve 678 * @crtc: which CRTC's vblank timestamp to retrieve
648 * @tvblank: Pointer to target struct timeval which should receive the timestamp 679 * @tvblank: Pointer to target struct timeval which should receive the timestamp
649 * @flags: Flags to pass to driver: 680 * @flags: Flags to pass to driver:
650 * 0 = Default. 681 * 0 = Default,
651 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler. 682 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
652 * 683 *
653 * Fetches the system timestamp corresponding to the time of the most recent 684 * Fetches the system timestamp corresponding to the time of the most recent
654 * vblank interval on specified crtc. May call into kms-driver to 685 * vblank interval on specified CRTC. May call into kms-driver to
655 * compute the timestamp with a high-precision GPU specific method. 686 * compute the timestamp with a high-precision GPU specific method.
656 * 687 *
657 * Returns zero if timestamp originates from uncorrected do_gettimeofday() 688 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
658 * call, i.e., it isn't very precisely locked to the true vblank. 689 * call, i.e., it isn't very precisely locked to the true vblank.
659 * 690 *
660 * Returns non-zero if timestamp is considered to be very precise. 691 * Returns:
692 * Non-zero if timestamp is considered to be very precise, zero otherwise.
661 */ 693 */
662u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc, 694u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
663 struct timeval *tvblank, unsigned flags) 695 struct timeval *tvblank, unsigned flags)
@@ -692,6 +724,9 @@ EXPORT_SYMBOL(drm_get_last_vbltimestamp);
692 * Fetches the "cooked" vblank count value that represents the number of 724 * Fetches the "cooked" vblank count value that represents the number of
693 * vblank events since the system was booted, including lost events due to 725 * vblank events since the system was booted, including lost events due to
694 * modesetting activity. 726 * modesetting activity.
727 *
728 * Returns:
729 * The software vblank counter.
695 */ 730 */
696u32 drm_vblank_count(struct drm_device *dev, int crtc) 731u32 drm_vblank_count(struct drm_device *dev, int crtc)
697{ 732{
@@ -710,8 +745,7 @@ EXPORT_SYMBOL(drm_vblank_count);
710 * Fetches the "cooked" vblank count value that represents the number of 745 * Fetches the "cooked" vblank count value that represents the number of
711 * vblank events since the system was booted, including lost events due to 746 * vblank events since the system was booted, including lost events due to
712 * modesetting activity. Returns corresponding system timestamp of the time 747 * modesetting activity. Returns corresponding system timestamp of the time
713 * of the vblank interval that corresponds to the current value vblank counter 748 * of the vblank interval that corresponds to the current vblank counter value.
714 * value.
715 */ 749 */
716u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc, 750u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
717 struct timeval *vblanktime) 751 struct timeval *vblanktime)
@@ -882,7 +916,7 @@ static int drm_vblank_enable(struct drm_device *dev, int crtc)
882 * Acquire a reference count on vblank events to avoid having them disabled 916 * Acquire a reference count on vblank events to avoid having them disabled
883 * while in use. 917 * while in use.
884 * 918 *
885 * RETURNS 919 * Returns:
886 * Zero on success, nonzero on failure. 920 * Zero on success, nonzero on failure.
887 */ 921 */
888int drm_vblank_get(struct drm_device *dev, int crtc) 922int drm_vblank_get(struct drm_device *dev, int crtc)
@@ -930,6 +964,13 @@ EXPORT_SYMBOL(drm_vblank_put);
930 * drm_vblank_off - disable vblank events on a CRTC 964 * drm_vblank_off - disable vblank events on a CRTC
931 * @dev: DRM device 965 * @dev: DRM device
932 * @crtc: CRTC in question 966 * @crtc: CRTC in question
967 *
968 * Drivers can use this function to shut down the vblank interrupt handling when
969 * disabling a crtc. This function ensures that the latest vblank frame count is
970 * stored so that drm_vblank_on() can restore it again.
971 *
972 * Drivers must use this function when the hardware vblank counter can get
973 * reset, e.g. when suspending.
933 */ 974 */
934void drm_vblank_off(struct drm_device *dev, int crtc) 975void drm_vblank_off(struct drm_device *dev, int crtc)
935{ 976{
@@ -966,6 +1007,11 @@ EXPORT_SYMBOL(drm_vblank_off);
966 * drm_vblank_on - enable vblank events on a CRTC 1007 * drm_vblank_on - enable vblank events on a CRTC
967 * @dev: DRM device 1008 * @dev: DRM device
968 * @crtc: CRTC in question 1009 * @crtc: CRTC in question
1010 *
1011 * This functions restores the vblank interrupt state captured with
1012 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1013 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1014 * in driver load code to reflect the current hardware state of the crtc.
969 */ 1015 */
970void drm_vblank_on(struct drm_device *dev, int crtc) 1016void drm_vblank_on(struct drm_device *dev, int crtc)
971{ 1017{
@@ -986,6 +1032,21 @@ EXPORT_SYMBOL(drm_vblank_on);
986 * 1032 *
987 * Account for vblank events across mode setting events, which will likely 1033 * Account for vblank events across mode setting events, which will likely
988 * reset the hardware frame counter. 1034 * reset the hardware frame counter.
1035 *
1036 * This is done by grabbing a temporary vblank reference to ensure that the
1037 * vblank interrupt keeps running across the modeset sequence. With this the
1038 * software-side vblank frame counting will ensure that there are no jumps or
1039 * discontinuities.
1040 *
1041 * Unfortunately this approach is racy and also doesn't work when the vblank
1042 * interrupt stops running, e.g. across system suspend resume. It is therefore
1043 * highly recommended that drivers use the newer drm_vblank_off() and
1044 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1045 * using "cooked" software vblank frame counters and not relying on any hardware
1046 * counters.
1047 *
1048 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1049 * again.
989 */ 1050 */
990void drm_vblank_pre_modeset(struct drm_device *dev, int crtc) 1051void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
991{ 1052{
@@ -1007,6 +1068,14 @@ void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1007} 1068}
1008EXPORT_SYMBOL(drm_vblank_pre_modeset); 1069EXPORT_SYMBOL(drm_vblank_pre_modeset);
1009 1070
1071/**
1072 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1073 * @dev: DRM device
1074 * @crtc: CRTC in question
1075 *
1076 * This function again drops the temporary vblank reference acquired in
1077 * drm_vblank_pre_modeset.
1078 */
1010void drm_vblank_post_modeset(struct drm_device *dev, int crtc) 1079void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1011{ 1080{
1012 unsigned long irqflags; 1081 unsigned long irqflags;
@@ -1028,7 +1097,7 @@ void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1028} 1097}
1029EXPORT_SYMBOL(drm_vblank_post_modeset); 1098EXPORT_SYMBOL(drm_vblank_post_modeset);
1030 1099
1031/** 1100/*
1032 * drm_modeset_ctl - handle vblank event counter changes across mode switch 1101 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1033 * @DRM_IOCTL_ARGS: standard ioctl arguments 1102 * @DRM_IOCTL_ARGS: standard ioctl arguments
1034 * 1103 *
@@ -1141,7 +1210,7 @@ err_put:
1141 return ret; 1210 return ret;
1142} 1211}
1143 1212
1144/** 1213/*
1145 * Wait for VBLANK. 1214 * Wait for VBLANK.
1146 * 1215 *
1147 * \param inode device inode. 1216 * \param inode device inode.
@@ -1152,7 +1221,7 @@ err_put:
1152 * 1221 *
1153 * This function enables the vblank interrupt on the pipe requested, then 1222 * This function enables the vblank interrupt on the pipe requested, then
1154 * sleeps waiting for the requested sequence number to occur, and drops 1223 * sleeps waiting for the requested sequence number to occur, and drops
1155 * the vblank interrupt refcount afterwards. (vblank irq disable follows that 1224 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1156 * after a timeout with no further vblank waits scheduled). 1225 * after a timeout with no further vblank waits scheduled).
1157 */ 1226 */
1158int drm_wait_vblank(struct drm_device *dev, void *data, 1227int drm_wait_vblank(struct drm_device *dev, void *data,