From 2d1a8a48ac68a835c42d8a31a02b8158cd599615 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Tue, 30 Aug 2011 18:16:33 -0400 Subject: gpu: Add export.h as required to drivers/gpu files. They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE Signed-off-by: Paul Gortmaker --- drivers/gpu/drm/drm_irq.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/gpu/drm/drm_irq.c') diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 3830e9e478c0..cb3794a00f98 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -40,6 +40,7 @@ #include #include +#include /* Access macro for slots in vblank timestamp ringbuffer. */ #define vblanktimestamp(dev, crtc, count) ( \ -- cgit v1.2.3 From bde4889aaa2d59c1febfeadd7f690be0ed143ed5 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Mon, 4 Jul 2011 12:52:27 +1000 Subject: drm: make sure drm_vblank_init() has been called before touching vbl_lock Signed-off-by: Ben Skeggs --- drivers/gpu/drm/drm_irq.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'drivers/gpu/drm/drm_irq.c') diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index cb3794a00f98..4d3760c63964 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -407,13 +407,16 @@ int drm_irq_uninstall(struct drm_device *dev) /* * Wake up any waiters so they don't hang. */ - spin_lock_irqsave(&dev->vbl_lock, irqflags); - for (i = 0; i < dev->num_crtcs; i++) { - DRM_WAKEUP(&dev->vbl_queue[i]); - dev->vblank_enabled[i] = 0; - dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i); + if (dev->num_crtcs) { + spin_lock_irqsave(&dev->vbl_lock, irqflags); + for (i = 0; i < dev->num_crtcs; i++) { + DRM_WAKEUP(&dev->vbl_queue[i]); + dev->vblank_enabled[i] = 0; + dev->last_vblank[i] = + dev->driver->get_vblank_counter(dev, i); + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); } - spin_unlock_irqrestore(&dev->vbl_lock, irqflags); if (!irq_enabled) return -EINVAL; -- cgit v1.2.3 From a6778e9e7fb57603f15344ceb30098a3f6b7caf4 Mon Sep 17 00:00:00 2001 From: Ilija Hadzic Date: Mon, 31 Oct 2011 13:11:57 -0400 Subject: drm: add some comments to drm_wait_vblank and drm_queue_vblank_event during the review of the fix for locks problems in drm_wait_vblank, a couple of false concerns were raised about how the drm_vblank_get and drm_vblank_put are used in this function; it turned out that the code is correct and that it cannot be simplified add a few comments to explain non-obvious flows in the code, to prevent "false alarms" in the future v2: incorporate comments received from Daniel Vetter Signed-off-by: Ilija Hadzic Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_irq.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_irq.c') diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index cb3794a00f98..aa3ac0125d90 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1125,6 +1125,7 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe, trace_drm_vblank_event_delivered(current->pid, pipe, vblwait->request.sequence); } else { + /* drm_handle_vblank_events will call drm_vblank_put */ list_add_tail(&e->base.link, &dev->vblank_event_list); vblwait->reply.sequence = vblwait->request.sequence; } @@ -1205,8 +1206,12 @@ int drm_wait_vblank(struct drm_device *dev, void *data, goto done; } - if (flags & _DRM_VBLANK_EVENT) + if (flags & _DRM_VBLANK_EVENT) { + /* must hold on to the vblank ref until the event fires + * drm_vblank_put will be called asynchronously + */ return drm_queue_vblank_event(dev, crtc, vblwait, file_priv); + } if ((flags & _DRM_VBLANK_NEXTONMISS) && (seq - vblwait->request.sequence) <= (1<<23)) { -- cgit v1.2.3 From d53dab3ae1a3c6b438738c3792c98ac63f0061f4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 23 Jul 2011 12:45:07 +0200 Subject: drm: Remove utterly bogus preempt_disable() sections commit 27641c3f (drm/vblank: Add support for precise vblank timestamping) adds preempt_disable()/enable() around a spin locked section with the comments: * Disable preemption, so vblank_time_lock is held as short as * possible, even under a kernel with PREEMPT_RT patches. /* Disable preemption while holding vblank_time_lock. Do * it explicitely to guard against PREEMPT_RT kernel. Just that this has never been tested on a RT kernel which would have granted that nonsense with a might_sleep() warning because dev->vblank_time_lock is converted to a "sleeping" spinlock on RT. So this is activly wrong on RT and superflous on mainline. Remove it. Signed-off-by: Thomas Gleixner Acked-by: Mario Kleiner Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_irq.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'drivers/gpu/drm/drm_irq.c') diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 68b756253f9f..44a5d0ad8b7c 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -110,10 +110,7 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) /* Prevent vblank irq processing while disabling vblank irqs, * so no updates of timestamps or count can happen after we've * disabled. Needed to prevent races in case of delayed irq's. - * Disable preemption, so vblank_time_lock is held as short as - * possible, even under a kernel with PREEMPT_RT patches. */ - preempt_disable(); spin_lock_irqsave(&dev->vblank_time_lock, irqflags); dev->driver->disable_vblank(dev, crtc); @@ -164,7 +161,6 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) clear_vblank_timestamps(dev, crtc); spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); - preempt_enable(); } static void vblank_disable_fn(unsigned long arg) @@ -889,10 +885,6 @@ 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_refcount[crtc]) == 1) { - /* Disable preemption while holding vblank_time_lock. Do - * it explicitely to guard against PREEMPT_RT kernel. - */ - preempt_disable(); spin_lock_irqsave(&dev->vblank_time_lock, irqflags2); if (!dev->vblank_enabled[crtc]) { /* Enable vblank irqs under vblank_time_lock protection. @@ -912,7 +904,6 @@ int drm_vblank_get(struct drm_device *dev, int crtc) } } spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2); - preempt_enable(); } else { if (!dev->vblank_enabled[crtc]) { atomic_dec(&dev->vblank_refcount[crtc]); -- cgit v1.2.3