diff options
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 461 |
1 files changed, 305 insertions, 156 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index ec5c3f4cdd01..0de123afdb34 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1,6 +1,5 @@ -/** - * \file drm_irq.c - * IRQ support +/* + * drm_irq.c IRQ and vblank support * * \author Rickard E. (Rik) Faith <faith@valinux.com> * \author Gareth Hughes <gareth@valinux.com> @@ -56,33 +55,6 @@ */ #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000 -/** - * Get interrupt from bus id. - * - * \param inode device inode. - * \param file_priv DRM file private. - * \param cmd command. - * \param arg user argument, pointing to a drm_irq_busid structure. - * \return zero on success or a negative number on failure. - * - * Finds the PCI device with the specified bus id and gets its IRQ number. - * This IOCTL is deprecated, and will now return EINVAL for any busid not equal - * to that of the device that this DRM instance attached to. - */ -int drm_irq_by_busid(struct drm_device *dev, void *data, - struct drm_file *file_priv) -{ - struct drm_irq_busid *p = data; - - if (!dev->driver->bus->irq_by_busid) - return -EINVAL; - - if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) - return -EINVAL; - - return dev->driver->bus->irq_by_busid(dev, p); -} - /* * Clear vblank timestamp buffer for a crtc. */ @@ -167,33 +139,40 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) static void vblank_disable_fn(unsigned long arg) { - struct drm_device *dev = (struct drm_device *)arg; + struct drm_vblank_crtc *vblank = (void *)arg; + struct drm_device *dev = vblank->dev; unsigned long irqflags; - int i; + int crtc = vblank->crtc; if (!dev->vblank_disable_allowed) return; - for (i = 0; i < dev->num_crtcs; i++) { - spin_lock_irqsave(&dev->vbl_lock, irqflags); - if (atomic_read(&dev->vblank[i].refcount) == 0 && - dev->vblank[i].enabled) { - DRM_DEBUG("disabling vblank on crtc %d\n", i); - vblank_disable_and_save(dev, i); - } - spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + spin_lock_irqsave(&dev->vbl_lock, irqflags); + if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) { + DRM_DEBUG("disabling vblank on crtc %d\n", crtc); + vblank_disable_and_save(dev, crtc); } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); } +/** + * drm_vblank_cleanup - cleanup vblank support + * @dev: DRM device + * + * This function cleans up any resources allocated in drm_vblank_init. + */ void drm_vblank_cleanup(struct drm_device *dev) { + int crtc; + /* Bail if the driver didn't call drm_vblank_init() */ if (dev->num_crtcs == 0) return; - del_timer_sync(&dev->vblank_disable_timer); - - vblank_disable_fn((unsigned long)dev); + for (crtc = 0; crtc < dev->num_crtcs; crtc++) { + del_timer_sync(&dev->vblank[crtc].disable_timer); + vblank_disable_fn((unsigned long)&dev->vblank[crtc]); + } kfree(dev->vblank); @@ -201,12 +180,20 @@ void drm_vblank_cleanup(struct drm_device *dev) } EXPORT_SYMBOL(drm_vblank_cleanup); +/** + * drm_vblank_init - initialize vblank support + * @dev: drm_device + * @num_crtcs: number of crtcs supported by @dev + * + * This function initializes vblank support for @num_crtcs display pipelines. + * + * Returns: + * Zero on success or a negative error code on failure. + */ int drm_vblank_init(struct drm_device *dev, int num_crtcs) { int i, ret = -ENOMEM; - setup_timer(&dev->vblank_disable_timer, vblank_disable_fn, - (unsigned long)dev); spin_lock_init(&dev->vbl_lock); spin_lock_init(&dev->vblank_time_lock); @@ -216,8 +203,13 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs) if (!dev->vblank) goto err; - for (i = 0; i < num_crtcs; i++) + for (i = 0; i < num_crtcs; i++) { + dev->vblank[i].dev = dev; + dev->vblank[i].crtc = i; init_waitqueue_head(&dev->vblank[i].queue); + setup_timer(&dev->vblank[i].disable_timer, vblank_disable_fn, + (unsigned long)&dev->vblank[i]); + } DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n"); @@ -261,42 +253,42 @@ static void drm_irq_vgaarb_nokms(void *cookie, bool state) } /** - * Install IRQ handler. - * - * \param dev DRM device. + * drm_irq_install - install IRQ handler + * @dev: DRM device + * @irq: IRQ number to install the handler for * * Initializes the IRQ related data. Installs the handler, calling the driver - * \c irq_preinstall() and \c irq_postinstall() functions - * before and after the installation. + * irq_preinstall() and irq_postinstall() functions before and after the + * installation. + * + * This is the simplified helper interface provided for drivers with no special + * needs. Drivers which need to install interrupt handlers for multiple + * interrupts must instead set drm_device->irq_enabled to signal the DRM core + * that vblank interrupts are available. + * + * Returns: + * Zero on success or a negative error code on failure. */ -int drm_irq_install(struct drm_device *dev) +int drm_irq_install(struct drm_device *dev, int irq) { int ret; unsigned long sh_flags = 0; - char *irqname; if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; - if (drm_dev_to_irq(dev) == 0) + if (irq == 0) return -EINVAL; - mutex_lock(&dev->struct_mutex); - /* Driver must have been initialized */ - if (!dev->dev_private) { - mutex_unlock(&dev->struct_mutex); + if (!dev->dev_private) return -EINVAL; - } - if (dev->irq_enabled) { - mutex_unlock(&dev->struct_mutex); + if (dev->irq_enabled) return -EBUSY; - } dev->irq_enabled = true; - mutex_unlock(&dev->struct_mutex); - DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev)); + DRM_DEBUG("irq=%d\n", irq); /* Before installing handler */ if (dev->driver->irq_preinstall) @@ -306,18 +298,11 @@ int drm_irq_install(struct drm_device *dev) if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED)) sh_flags = IRQF_SHARED; - if (dev->devname) - irqname = dev->devname; - else - irqname = dev->driver->name; - - ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler, - sh_flags, irqname, dev); + ret = request_irq(irq, dev->driver->irq_handler, + sh_flags, dev->driver->name, dev); if (ret < 0) { - mutex_lock(&dev->struct_mutex); dev->irq_enabled = false; - mutex_unlock(&dev->struct_mutex); return ret; } @@ -329,12 +314,12 @@ int drm_irq_install(struct drm_device *dev) ret = dev->driver->irq_postinstall(dev); if (ret < 0) { - mutex_lock(&dev->struct_mutex); dev->irq_enabled = false; - mutex_unlock(&dev->struct_mutex); if (!drm_core_check_feature(dev, DRIVER_MODESET)) vga_client_register(dev->pdev, NULL, NULL, NULL); - free_irq(drm_dev_to_irq(dev), dev); + free_irq(irq, dev); + } else { + dev->irq = irq; } return ret; @@ -342,11 +327,20 @@ int drm_irq_install(struct drm_device *dev) EXPORT_SYMBOL(drm_irq_install); /** - * Uninstall the IRQ handler. + * drm_irq_uninstall - uninstall the IRQ handler + * @dev: DRM device + * + * Calls the driver's irq_uninstall() function and unregisters the IRQ handler. + * This should only be called by drivers which used drm_irq_install() to set up + * their interrupt handler. Other drivers must only reset + * drm_device->irq_enabled to false. * - * \param dev DRM device. + * Note that for kernel modesetting drivers it is a bug if this function fails. + * The sanity checks are only to catch buggy user modesetting drivers which call + * the same function through an ioctl. * - * Calls the driver's \c irq_uninstall() function, and stops the irq. + * Returns: + * Zero on success or a negative error code on failure. */ int drm_irq_uninstall(struct drm_device *dev) { @@ -357,10 +351,8 @@ int drm_irq_uninstall(struct drm_device *dev) if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; - mutex_lock(&dev->struct_mutex); irq_enabled = dev->irq_enabled; dev->irq_enabled = false; - mutex_unlock(&dev->struct_mutex); /* * Wake up any waiters so they don't hang. @@ -379,7 +371,7 @@ int drm_irq_uninstall(struct drm_device *dev) if (!irq_enabled) return -EINVAL; - DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev)); + DRM_DEBUG("irq=%d\n", dev->irq); if (!drm_core_check_feature(dev, DRIVER_MODESET)) vga_client_register(dev->pdev, NULL, NULL, NULL); @@ -387,13 +379,13 @@ int drm_irq_uninstall(struct drm_device *dev) if (dev->driver->irq_uninstall) dev->driver->irq_uninstall(dev); - free_irq(drm_dev_to_irq(dev), dev); + free_irq(dev->irq, dev); return 0; } EXPORT_SYMBOL(drm_irq_uninstall); -/** +/* * IRQ control ioctl. * * \param inode device inode. @@ -408,43 +400,52 @@ int drm_control(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_control *ctl = data; + int ret = 0, irq; /* if we haven't irq we fallback for compatibility reasons - * this used to be a separate function in drm_dma.h */ + if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) + return 0; + if (drm_core_check_feature(dev, DRIVER_MODESET)) + return 0; + /* UMS was only ever support on pci devices. */ + if (WARN_ON(!dev->pdev)) + return -EINVAL; switch (ctl->func) { case DRM_INST_HANDLER: - if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) - return 0; - if (drm_core_check_feature(dev, DRIVER_MODESET)) - return 0; + irq = dev->pdev->irq; + if (dev->if_version < DRM_IF_VERSION(1, 2) && - ctl->irq != drm_dev_to_irq(dev)) + ctl->irq != irq) return -EINVAL; - return drm_irq_install(dev); + mutex_lock(&dev->struct_mutex); + ret = drm_irq_install(dev, irq); + mutex_unlock(&dev->struct_mutex); + + return ret; case DRM_UNINST_HANDLER: - if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) - return 0; - if (drm_core_check_feature(dev, DRIVER_MODESET)) - return 0; - return drm_irq_uninstall(dev); + mutex_lock(&dev->struct_mutex); + ret = drm_irq_uninstall(dev); + mutex_unlock(&dev->struct_mutex); + + return ret; default: return -EINVAL; } } /** - * drm_calc_timestamping_constants - Calculate vblank timestamp constants - * - * @crtc drm_crtc whose timestamp constants should be updated. - * @mode display mode containing the scanout timings + * drm_calc_timestamping_constants - calculate vblank timestamp constants + * @crtc: drm_crtc whose timestamp constants should be updated. + * @mode: display mode containing the scanout timings * * Calculate and store various constants which are later * needed by vblank and swap-completion timestamping, e.g, * by drm_calc_vbltimestamp_from_scanoutpos(). They are - * derived from crtc's true scanout timing, so they take + * derived from CRTC's true scanout timing, so they take * things like panel scaling or other adjustments into account. */ void drm_calc_timestamping_constants(struct drm_crtc *crtc, @@ -489,11 +490,22 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, EXPORT_SYMBOL(drm_calc_timestamping_constants); /** - * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms - * drivers. Implements calculation of exact vblank timestamps from - * given drm_display_mode timings and current video scanout position - * of a crtc. This can be called from within get_vblank_timestamp() - * implementation of a kms driver to implement the actual timestamping. + * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper + * @dev: DRM device + * @crtc: Which CRTC's vblank timestamp to retrieve + * @max_error: Desired maximum allowable error in timestamps (nanosecs) + * On return contains true maximum error of timestamp + * @vblank_time: Pointer to struct timeval which should receive the timestamp + * @flags: Flags to pass to driver: + * 0 = Default, + * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler + * @refcrtc: CRTC which defines scanout timing + * @mode: mode which defines the scanout timings + * + * Implements calculation of exact vblank timestamps from given drm_display_mode + * timings and current video scanout position of a CRTC. This can be called from + * within get_vblank_timestamp() implementation of a kms driver to implement the + * actual timestamping. * * Should return timestamps conforming to the OML_sync_control OpenML * extension specification. The timestamp corresponds to the end of @@ -508,21 +520,11 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); * returns as no operation if a doublescan or interlaced video mode is * active. Higher level code is expected to handle this. * - * @dev: DRM device. - * @crtc: Which crtc's vblank timestamp to retrieve. - * @max_error: Desired maximum allowable error in timestamps (nanosecs). - * On return contains true maximum error of timestamp. - * @vblank_time: Pointer to struct timeval which should receive the timestamp. - * @flags: Flags to pass to driver: - * 0 = Default. - * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler. - * @refcrtc: drm_crtc* of crtc which defines scanout timing. - * @mode: mode which defines the scanout timings - * - * Returns negative value on error, failure or if not supported in current + * Returns: + * Negative value on error, failure or if not supported in current * video mode: * - * -EINVAL - Invalid crtc. + * -EINVAL - Invalid CRTC. * -EAGAIN - Temporary unavailable, e.g., called before initial modeset. * -ENOTSUPP - Function not supported in current display mode. * -EIO - Failed, e.g., due to failed scanout position query. @@ -671,23 +673,23 @@ static struct timeval get_drm_timestamp(void) /** * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent - * vblank interval. - * + * vblank interval * @dev: DRM device - * @crtc: which crtc's vblank timestamp to retrieve + * @crtc: which CRTC's vblank timestamp to retrieve * @tvblank: Pointer to target struct timeval which should receive the timestamp * @flags: Flags to pass to driver: - * 0 = Default. - * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler. + * 0 = Default, + * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler * * Fetches the system timestamp corresponding to the time of the most recent - * vblank interval on specified crtc. May call into kms-driver to + * vblank interval on specified CRTC. May call into kms-driver to * compute the timestamp with a high-precision GPU specific method. * * Returns zero if timestamp originates from uncorrected do_gettimeofday() * call, i.e., it isn't very precisely locked to the true vblank. * - * Returns non-zero if timestamp is considered to be very precise. + * Returns: + * Non-zero if timestamp is considered to be very precise, zero otherwise. */ u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc, struct timeval *tvblank, unsigned flags) @@ -722,6 +724,9 @@ EXPORT_SYMBOL(drm_get_last_vbltimestamp); * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. + * + * Returns: + * The software vblank counter. */ u32 drm_vblank_count(struct drm_device *dev, int crtc) { @@ -740,8 +745,7 @@ EXPORT_SYMBOL(drm_vblank_count); * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. Returns corresponding system timestamp of the time - * of the vblank interval that corresponds to the current value vblank counter - * value. + * of the vblank interval that corresponds to the current vblank counter value. */ u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc, struct timeval *vblanktime) @@ -870,6 +874,42 @@ static void drm_update_vblank_count(struct drm_device *dev, int crtc) } /** + * drm_vblank_enable - enable the vblank interrupt on a CRTC + * @dev: DRM device + * @crtc: CRTC in question + */ +static int drm_vblank_enable(struct drm_device *dev, int crtc) +{ + int ret = 0; + + assert_spin_locked(&dev->vbl_lock); + + spin_lock(&dev->vblank_time_lock); + + if (!dev->vblank[crtc].enabled) { + /* + * Enable vblank irqs under vblank_time_lock protection. + * All vblank count & timestamp updates are held off + * until we are done reinitializing master counter and + * timestamps. Filtercode in drm_handle_vblank() will + * prevent double-accounting of same vblank interval. + */ + ret = dev->driver->enable_vblank(dev, crtc); + DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret); + if (ret) + atomic_dec(&dev->vblank[crtc].refcount); + else { + dev->vblank[crtc].enabled = true; + drm_update_vblank_count(dev, crtc); + } + } + + spin_unlock(&dev->vblank_time_lock); + + return ret; +} + +/** * drm_vblank_get - get a reference count on vblank events * @dev: DRM device * @crtc: which CRTC to own @@ -877,36 +917,20 @@ static void drm_update_vblank_count(struct drm_device *dev, int crtc) * Acquire a reference count on vblank events to avoid having them disabled * while in use. * - * RETURNS + * This is the legacy version of drm_crtc_vblank_get(). + * + * Returns: * Zero on success, nonzero on failure. */ int drm_vblank_get(struct drm_device *dev, int crtc) { - unsigned long irqflags, irqflags2; + unsigned long irqflags; int ret = 0; spin_lock_irqsave(&dev->vbl_lock, irqflags); /* Going from 0->1 means we have to enable interrupts again */ if (atomic_add_return(1, &dev->vblank[crtc].refcount) == 1) { - spin_lock_irqsave(&dev->vblank_time_lock, irqflags2); - if (!dev->vblank[crtc].enabled) { - /* Enable vblank irqs under vblank_time_lock protection. - * All vblank count & timestamp updates are held off - * until we are done reinitializing master counter and - * timestamps. Filtercode in drm_handle_vblank() will - * prevent double-accounting of same vblank interval. - */ - ret = dev->driver->enable_vblank(dev, crtc); - DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", - crtc, ret); - if (ret) - atomic_dec(&dev->vblank[crtc].refcount); - else { - dev->vblank[crtc].enabled = true; - drm_update_vblank_count(dev, crtc); - } - } - spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2); + ret = drm_vblank_enable(dev, crtc); } else { if (!dev->vblank[crtc].enabled) { atomic_dec(&dev->vblank[crtc].refcount); @@ -920,12 +944,32 @@ int drm_vblank_get(struct drm_device *dev, int crtc) EXPORT_SYMBOL(drm_vblank_get); /** + * drm_crtc_vblank_get - get a reference count on vblank events + * @crtc: which CRTC to own + * + * Acquire a reference count on vblank events to avoid having them disabled + * while in use. + * + * This is the native kms version of drm_vblank_off(). + * + * Returns: + * Zero on success, nonzero on failure. + */ +int drm_crtc_vblank_get(struct drm_crtc *crtc) +{ + return drm_vblank_get(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_get); + +/** * drm_vblank_put - give up ownership of vblank events * @dev: DRM device * @crtc: which counter to give up * * Release ownership of a given vblank counter, turning off interrupts * if possible. Disable interrupts after drm_vblank_offdelay milliseconds. + * + * This is the legacy version of drm_crtc_vblank_put(). */ void drm_vblank_put(struct drm_device *dev, int crtc) { @@ -934,17 +978,39 @@ void drm_vblank_put(struct drm_device *dev, int crtc) /* Last user schedules interrupt disable */ if (atomic_dec_and_test(&dev->vblank[crtc].refcount) && (drm_vblank_offdelay > 0)) - mod_timer(&dev->vblank_disable_timer, + mod_timer(&dev->vblank[crtc].disable_timer, jiffies + ((drm_vblank_offdelay * HZ)/1000)); } EXPORT_SYMBOL(drm_vblank_put); /** + * drm_crtc_vblank_put - give up ownership of vblank events + * @crtc: which counter to give up + * + * Release ownership of a given vblank counter, turning off interrupts + * if possible. Disable interrupts after drm_vblank_offdelay milliseconds. + * + * This is the native kms version of drm_vblank_put(). + */ +void drm_crtc_vblank_put(struct drm_crtc *crtc) +{ + drm_vblank_put(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_put); + +/** * drm_vblank_off - disable vblank events on a CRTC * @dev: DRM device * @crtc: CRTC in question * - * Caller must hold event lock. + * Drivers can use this function to shut down the vblank interrupt handling when + * disabling a crtc. This function ensures that the latest vblank frame count is + * stored so that drm_vblank_on() can restore it again. + * + * Drivers must use this function when the hardware vblank counter can get + * reset, e.g. when suspending. + * + * This is the legacy version of drm_crtc_vblank_off(). */ void drm_vblank_off(struct drm_device *dev, int crtc) { @@ -978,12 +1044,87 @@ void drm_vblank_off(struct drm_device *dev, int crtc) EXPORT_SYMBOL(drm_vblank_off); /** + * drm_crtc_vblank_off - disable vblank events on a CRTC + * @crtc: CRTC in question + * + * Drivers can use this function to shut down the vblank interrupt handling when + * disabling a crtc. This function ensures that the latest vblank frame count is + * stored so that drm_vblank_on can restore it again. + * + * Drivers must use this function when the hardware vblank counter can get + * reset, e.g. when suspending. + * + * This is the native kms version of drm_vblank_off(). + */ +void drm_crtc_vblank_off(struct drm_crtc *crtc) +{ + drm_vblank_off(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_off); + +/** + * drm_vblank_on - enable vblank events on a CRTC + * @dev: DRM device + * @crtc: CRTC in question + * + * This functions restores the vblank interrupt state captured with + * drm_vblank_off() again. Note that calls to drm_vblank_on() and + * drm_vblank_off() can be unbalanced and so can also be unconditionaly called + * in driver load code to reflect the current hardware state of the crtc. + * + * This is the legacy version of drm_crtc_vblank_on(). + */ +void drm_vblank_on(struct drm_device *dev, int crtc) +{ + unsigned long irqflags; + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + /* re-enable interrupts if there's are users left */ + if (atomic_read(&dev->vblank[crtc].refcount) != 0) + WARN_ON(drm_vblank_enable(dev, crtc)); + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); +} +EXPORT_SYMBOL(drm_vblank_on); + +/** + * drm_crtc_vblank_on - enable vblank events on a CRTC + * @crtc: CRTC in question + * + * This functions restores the vblank interrupt state captured with + * drm_vblank_off() again. Note that calls to drm_vblank_on() and + * drm_vblank_off() can be unbalanced and so can also be unconditionaly called + * in driver load code to reflect the current hardware state of the crtc. + * + * This is the native kms version of drm_vblank_on(). + */ +void drm_crtc_vblank_on(struct drm_crtc *crtc) +{ + drm_vblank_on(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_on); + +/** * drm_vblank_pre_modeset - account for vblanks across mode sets * @dev: DRM device * @crtc: CRTC in question * * Account for vblank events across mode setting events, which will likely * reset the hardware frame counter. + * + * This is done by grabbing a temporary vblank reference to ensure that the + * vblank interrupt keeps running across the modeset sequence. With this the + * software-side vblank frame counting will ensure that there are no jumps or + * discontinuities. + * + * Unfortunately this approach is racy and also doesn't work when the vblank + * interrupt stops running, e.g. across system suspend resume. It is therefore + * highly recommended that drivers use the newer drm_vblank_off() and + * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when + * using "cooked" software vblank frame counters and not relying on any hardware + * counters. + * + * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc + * again. */ void drm_vblank_pre_modeset(struct drm_device *dev, int crtc) { @@ -1005,6 +1146,14 @@ void drm_vblank_pre_modeset(struct drm_device *dev, int crtc) } EXPORT_SYMBOL(drm_vblank_pre_modeset); +/** + * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes + * @dev: DRM device + * @crtc: CRTC in question + * + * This function again drops the temporary vblank reference acquired in + * drm_vblank_pre_modeset. + */ void drm_vblank_post_modeset(struct drm_device *dev, int crtc) { unsigned long irqflags; @@ -1026,7 +1175,7 @@ void drm_vblank_post_modeset(struct drm_device *dev, int crtc) } EXPORT_SYMBOL(drm_vblank_post_modeset); -/** +/* * drm_modeset_ctl - handle vblank event counter changes across mode switch * @DRM_IOCTL_ARGS: standard ioctl arguments * @@ -1139,7 +1288,7 @@ err_put: return ret; } -/** +/* * Wait for VBLANK. * * \param inode device inode. @@ -1150,7 +1299,7 @@ err_put: * * This function enables the vblank interrupt on the pipe requested, then * sleeps waiting for the requested sequence number to occur, and drops - * the vblank interrupt refcount afterwards. (vblank irq disable follows that + * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that * after a timeout with no further vblank waits scheduled). */ int drm_wait_vblank(struct drm_device *dev, void *data, @@ -1160,9 +1309,8 @@ int drm_wait_vblank(struct drm_device *dev, void *data, int ret; unsigned int flags, seq, crtc, high_crtc; - if (drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) - if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled)) - return -EINVAL; + if (!dev->irq_enabled) + return -EINVAL; if (vblwait->request.type & _DRM_VBLANK_SIGNAL) return -EINVAL; @@ -1222,6 +1370,7 @@ int drm_wait_vblank(struct drm_device *dev, void *data, DRM_WAIT_ON(ret, dev->vblank[crtc].queue, 3 * HZ, (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) <= (1 << 23)) || + !dev->vblank[crtc].enabled || !dev->irq_enabled)); if (ret != -EINTR) { |