From 0c65884f355ae4eed16696ae13c788420b0284dc Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Wed, 19 Feb 2014 19:36:08 +0200 Subject: drm: Make the vblank disable timer per-crtc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently there's one per-device vblank disable timer, and it gets reset wheneven the vblank refcount for any crtc drops to zero. That means that one crtc could accidentally be keeping the vblank interrupts for other crtcs enabled even if there are no users for them. Make the disable timer per-crtc to avoid this issue. Signed-off-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- include/drm/drmP.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 12f10bc2395f..9d982d483f12 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1024,14 +1024,17 @@ struct drm_pending_vblank_event { }; struct drm_vblank_crtc { + struct drm_device *dev; /* pointer to the drm_device */ wait_queue_head_t queue; /**< VBLANK wait queue */ struct timeval time[DRM_VBLANKTIME_RBSIZE]; /**< timestamp of current count */ + struct timer_list disable_timer; /* delayed disable timer */ atomic_t count; /**< number of VBLANK interrupts */ atomic_t refcount; /* number of users of vblank interruptsper crtc */ u32 last; /* protected by dev->vbl_lock, used */ /* for wraparound handling */ u32 last_wait; /* Last vblank seqno waited per CRTC */ unsigned int inmodeset; /* Display driver is setting mode */ + int crtc; /* crtc index */ bool enabled; /* so we don't call enable more than once per disable */ }; @@ -1119,7 +1122,6 @@ struct drm_device { spinlock_t vblank_time_lock; /**< Protects vblank count and time updates during vblank enable/disable */ spinlock_t vbl_lock; - struct timer_list vblank_disable_timer; u32 max_vblank_count; /**< size of vblank counter register */ -- cgit v1.2.3 From a3f430afdc08e71b4f99ed768106a10dd50ead29 Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Wed, 19 Feb 2014 21:29:49 +0200 Subject: drm: Add drm_vblank_on() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit drm_vblank_off() will turn off vblank interrupts, but as long as the refcount is elevated drm_vblank_get() will not re-enable them. This is a problem is someone is holding a vblank reference while a modeset is happening, and the driver requires vblank interrupt to work during that time. Add drm_vblank_on() as a counterpart to drm_vblank_off() which will re-enabled vblank interrupts if the refcount is already elevated. This will allow drivers to choose the specific places in the modeset sequence at which vblank interrupts get disabled and enabled. Signed-off-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_irq.c | 72 ++++++++++++++++++++++++++---------- drivers/gpu/drm/i915/intel_display.c | 8 ++++ include/drm/drmP.h | 1 + 3 files changed, 62 insertions(+), 19 deletions(-) (limited to 'include') diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 13d671ed3421..dd786d84daab 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -839,6 +839,41 @@ static void drm_update_vblank_count(struct drm_device *dev, int crtc) smp_mb__after_atomic_inc(); } +/** + * 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 @@ -858,25 +893,7 @@ int drm_vblank_get(struct drm_device *dev, int crtc) 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(&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); + ret = drm_vblank_enable(dev, crtc); } else { if (!dev->vblank[crtc].enabled) { atomic_dec(&dev->vblank[crtc].refcount); @@ -945,6 +962,23 @@ void drm_vblank_off(struct drm_device *dev, int crtc) } EXPORT_SYMBOL(drm_vblank_off); +/** + * drm_vblank_on - enable vblank events on a CRTC + * @dev: DRM device + * @crtc: CRTC in question + */ +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_vblank_pre_modeset - account for vblanks across mode sets * @dev: DRM device diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b39d0367dd68..858c393b051f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3739,6 +3739,8 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc) * happening. */ intel_wait_for_vblank(dev, intel_crtc->pipe); + + drm_vblank_on(dev, pipe); } /* IPS only exists on ULT machines and is tied to pipe A. */ @@ -3830,6 +3832,8 @@ static void haswell_crtc_enable(struct drm_crtc *crtc) * to change the workaround. */ haswell_mode_set_planes_workaround(intel_crtc); ilk_crtc_enable_planes(crtc); + + drm_vblank_on(dev, pipe); } static void ironlake_pfit_disable(struct intel_crtc *crtc) @@ -4353,6 +4357,8 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc) for_each_encoder_on_crtc(dev, crtc, encoder) encoder->enable(encoder); + + drm_vblank_on(dev, pipe); } static void i9xx_crtc_enable(struct drm_crtc *crtc) @@ -4400,6 +4406,8 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc) for_each_encoder_on_crtc(dev, crtc, encoder) encoder->enable(encoder); + + drm_vblank_on(dev, pipe); } static void i9xx_pfit_disable(struct intel_crtc *crtc) diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 9d982d483f12..7339b2b00724 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1360,6 +1360,7 @@ extern bool drm_handle_vblank(struct drm_device *dev, int crtc); extern int drm_vblank_get(struct drm_device *dev, int crtc); extern void drm_vblank_put(struct drm_device *dev, int crtc); extern void drm_vblank_off(struct drm_device *dev, int crtc); +extern void drm_vblank_on(struct drm_device *dev, int crtc); extern void drm_vblank_cleanup(struct drm_device *dev); extern u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc, struct timeval *tvblank, unsigned flags); -- cgit v1.2.3