From dc1336ff4fe08ae7cfe8301bfd7f0b2cfd31d20a Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Tue, 6 Jan 2009 10:21:24 -0800 Subject: drm/i915: set vblank enabled flag correctly across IRQ install/uninstall In the absence of kernel mode setting, many drivers disable IRQs across VT switch. The core DRM vblank code is missing a check for this case however; even after IRQ disable, the vblank code will still have the vblank_enabled flag set, so unless we track the fact that they're disabled at IRQ uninstall time, when we VT switch back in we won't actually re-enable them, which means any apps waiting on vblank before the switch will hang. This patch does that and also adds a sanity check to the wait condition to look for the irq_enabled flag in general, as well as adding a wakeup to the IRQ uninstall path. Fixes fdo bug #18879 with compiz hangs at VT switch. Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_irq.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 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 724e505873cf..477caa1b1e4b 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -267,7 +267,8 @@ EXPORT_SYMBOL(drm_irq_install); */ int drm_irq_uninstall(struct drm_device * dev) { - int irq_enabled; + unsigned long irqflags; + int irq_enabled, i; if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; @@ -277,6 +278,16 @@ int drm_irq_uninstall(struct drm_device * dev) dev->irq_enabled = 0; mutex_unlock(&dev->struct_mutex); + /* + * 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; + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + if (!irq_enabled) return -EINVAL; @@ -652,8 +663,9 @@ int drm_wait_vblank(struct drm_device *dev, void *data, vblwait->request.sequence, crtc); dev->last_vblank_wait[crtc] = vblwait->request.sequence; DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ, - ((drm_vblank_count(dev, crtc) - - vblwait->request.sequence) <= (1 << 23))); + (((drm_vblank_count(dev, crtc) - + vblwait->request.sequence) <= (1 << 23)) || + !dev->irq_enabled)); if (ret != -EINTR) { struct timeval now; -- cgit v1.2.3 From 30b23634084d95781f7611c0713cb551a0c0a152 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Tue, 27 Jan 2009 21:19:41 -0800 Subject: drm: Rip out the racy, unused vblank signal code. Schedule a vblank signal, kill the process, and we'll go walking over freed memory. Given that no open-source userland exists using this, nor have I ever heard of a consumer, just let this code die. Signed-off-by: Eric Anholt Requested-by: Linus Torvalds Acked-by: Dave Airlie Signed-off-by: Linus Torvalds --- drivers/gpu/drm/drm_irq.c | 161 +++++++--------------------------------------- include/drm/drm.h | 2 +- include/drm/drmP.h | 9 --- 3 files changed, 24 insertions(+), 148 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 477caa1b1e4b..69aa0ab28403 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -106,8 +106,6 @@ void drm_vblank_cleanup(struct drm_device *dev) drm_free(dev->vbl_queue, sizeof(*dev->vbl_queue) * dev->num_crtcs, DRM_MEM_DRIVER); - drm_free(dev->vbl_sigs, sizeof(*dev->vbl_sigs) * dev->num_crtcs, - DRM_MEM_DRIVER); drm_free(dev->_vblank_count, sizeof(*dev->_vblank_count) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->vblank_refcount, sizeof(*dev->vblank_refcount) * @@ -132,7 +130,6 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs) setup_timer(&dev->vblank_disable_timer, vblank_disable_fn, (unsigned long)dev); spin_lock_init(&dev->vbl_lock); - atomic_set(&dev->vbl_signal_pending, 0); dev->num_crtcs = num_crtcs; dev->vbl_queue = drm_alloc(sizeof(wait_queue_head_t) * num_crtcs, @@ -140,11 +137,6 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs) if (!dev->vbl_queue) goto err; - dev->vbl_sigs = drm_alloc(sizeof(struct list_head) * num_crtcs, - DRM_MEM_DRIVER); - if (!dev->vbl_sigs) - goto err; - dev->_vblank_count = drm_alloc(sizeof(atomic_t) * num_crtcs, DRM_MEM_DRIVER); if (!dev->_vblank_count) @@ -177,7 +169,6 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs) /* Zero per-crtc vblank stuff */ for (i = 0; i < num_crtcs; i++) { init_waitqueue_head(&dev->vbl_queue[i]); - INIT_LIST_HEAD(&dev->vbl_sigs[i]); atomic_set(&dev->_vblank_count[i], 0); atomic_set(&dev->vblank_refcount[i], 0); } @@ -540,15 +531,10 @@ out: * \param data user argument, pointing to a drm_wait_vblank structure. * \return zero on success or a negative number on failure. * - * Verifies the IRQ is installed. - * - * If a signal is requested checks if this task has already scheduled the same signal - * for the same vblank sequence number - nothing to be done in - * that case. If the number of tasks waiting for the interrupt exceeds 100 the - * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this - * task. - * - * If a signal is not requested, then calls vblank_wait(). + * 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 + * after a timeout with no further vblank waits scheduled). */ int drm_wait_vblank(struct drm_device *dev, void *data, struct drm_file *file_priv) @@ -560,6 +546,9 @@ int drm_wait_vblank(struct drm_device *dev, void *data, if ((!dev->pdev->irq) || (!dev->irq_enabled)) return -EINVAL; + if (vblwait->request.type & _DRM_VBLANK_SIGNAL) + return -EINVAL; + if (vblwait->request.type & ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) { DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n", @@ -597,89 +586,26 @@ int drm_wait_vblank(struct drm_device *dev, void *data, vblwait->request.sequence = seq + 1; } - if (flags & _DRM_VBLANK_SIGNAL) { - unsigned long irqflags; - struct list_head *vbl_sigs = &dev->vbl_sigs[crtc]; - struct drm_vbl_sig *vbl_sig; - - spin_lock_irqsave(&dev->vbl_lock, irqflags); - - /* Check if this task has already scheduled the same signal - * for the same vblank sequence number; nothing to be done in - * that case - */ - list_for_each_entry(vbl_sig, vbl_sigs, head) { - if (vbl_sig->sequence == vblwait->request.sequence - && vbl_sig->info.si_signo == - vblwait->request.signal - && vbl_sig->task == current) { - spin_unlock_irqrestore(&dev->vbl_lock, - irqflags); - vblwait->reply.sequence = seq; - goto done; - } - } - - if (atomic_read(&dev->vbl_signal_pending) >= 100) { - spin_unlock_irqrestore(&dev->vbl_lock, irqflags); - ret = -EBUSY; - goto done; - } - - spin_unlock_irqrestore(&dev->vbl_lock, irqflags); - - vbl_sig = drm_calloc(1, sizeof(struct drm_vbl_sig), - DRM_MEM_DRIVER); - if (!vbl_sig) { - ret = -ENOMEM; - goto done; - } - - /* Get a refcount on the vblank, which will be released by - * drm_vbl_send_signals(). - */ - ret = drm_vblank_get(dev, crtc); - if (ret) { - drm_free(vbl_sig, sizeof(struct drm_vbl_sig), - DRM_MEM_DRIVER); - goto done; - } - - atomic_inc(&dev->vbl_signal_pending); - - vbl_sig->sequence = vblwait->request.sequence; - vbl_sig->info.si_signo = vblwait->request.signal; - vbl_sig->task = current; + DRM_DEBUG("waiting on vblank count %d, crtc %d\n", + vblwait->request.sequence, crtc); + dev->last_vblank_wait[crtc] = vblwait->request.sequence; + DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ, + (((drm_vblank_count(dev, crtc) - + vblwait->request.sequence) <= (1 << 23)) || + !dev->irq_enabled)); - spin_lock_irqsave(&dev->vbl_lock, irqflags); - - list_add_tail(&vbl_sig->head, vbl_sigs); + if (ret != -EINTR) { + struct timeval now; - spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + do_gettimeofday(&now); - vblwait->reply.sequence = seq; + vblwait->reply.tval_sec = now.tv_sec; + vblwait->reply.tval_usec = now.tv_usec; + vblwait->reply.sequence = drm_vblank_count(dev, crtc); + DRM_DEBUG("returning %d to client\n", + vblwait->reply.sequence); } else { - DRM_DEBUG("waiting on vblank count %d, crtc %d\n", - vblwait->request.sequence, crtc); - dev->last_vblank_wait[crtc] = vblwait->request.sequence; - DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ, - (((drm_vblank_count(dev, crtc) - - vblwait->request.sequence) <= (1 << 23)) || - !dev->irq_enabled)); - - if (ret != -EINTR) { - struct timeval now; - - do_gettimeofday(&now); - - vblwait->reply.tval_sec = now.tv_sec; - vblwait->reply.tval_usec = now.tv_usec; - vblwait->reply.sequence = drm_vblank_count(dev, crtc); - DRM_DEBUG("returning %d to client\n", - vblwait->reply.sequence); - } else { - DRM_DEBUG("vblank wait interrupted by signal\n"); - } + DRM_DEBUG("vblank wait interrupted by signal\n"); } done: @@ -687,46 +613,6 @@ done: return ret; } -/** - * Send the VBLANK signals. - * - * \param dev DRM device. - * \param crtc CRTC where the vblank event occurred - * - * Sends a signal for each task in drm_device::vbl_sigs and empties the list. - * - * If a signal is not requested, then calls vblank_wait(). - */ -static void drm_vbl_send_signals(struct drm_device *dev, int crtc) -{ - struct drm_vbl_sig *vbl_sig, *tmp; - struct list_head *vbl_sigs; - unsigned int vbl_seq; - unsigned long flags; - - spin_lock_irqsave(&dev->vbl_lock, flags); - - vbl_sigs = &dev->vbl_sigs[crtc]; - vbl_seq = drm_vblank_count(dev, crtc); - - list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, head) { - if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) { - vbl_sig->info.si_code = vbl_seq; - send_sig_info(vbl_sig->info.si_signo, - &vbl_sig->info, vbl_sig->task); - - list_del(&vbl_sig->head); - - drm_free(vbl_sig, sizeof(*vbl_sig), - DRM_MEM_DRIVER); - atomic_dec(&dev->vbl_signal_pending); - drm_vblank_put(dev, crtc); - } - } - - spin_unlock_irqrestore(&dev->vbl_lock, flags); -} - /** * drm_handle_vblank - handle a vblank event * @dev: DRM device @@ -739,6 +625,5 @@ void drm_handle_vblank(struct drm_device *dev, int crtc) { atomic_inc(&dev->_vblank_count[crtc]); DRM_WAKEUP(&dev->vbl_queue[crtc]); - drm_vbl_send_signals(dev, crtc); } EXPORT_SYMBOL(drm_handle_vblank); diff --git a/include/drm/drm.h b/include/drm/drm.h index 32e5096554e9..8e77357334ad 100644 --- a/include/drm/drm.h +++ b/include/drm/drm.h @@ -458,7 +458,7 @@ enum drm_vblank_seq_type { _DRM_VBLANK_FLIP = 0x8000000, /**< Scheduled buffer swap should flip */ _DRM_VBLANK_NEXTONMISS = 0x10000000, /**< If missed, wait for next vblank */ _DRM_VBLANK_SECONDARY = 0x20000000, /**< Secondary display controller */ - _DRM_VBLANK_SIGNAL = 0x40000000 /**< Send signal instead of blocking */ + _DRM_VBLANK_SIGNAL = 0x40000000 /**< Send signal instead of blocking, unsupported */ }; #define _DRM_VBLANK_TYPES_MASK (_DRM_VBLANK_ABSOLUTE | _DRM_VBLANK_RELATIVE) diff --git a/include/drm/drmP.h b/include/drm/drmP.h index afb7858c068d..8190b9bcc2d9 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -545,13 +545,6 @@ struct drm_ctx_list { struct drm_file *tag; /**< associated fd private data */ }; -struct drm_vbl_sig { - struct list_head head; - unsigned int sequence; - struct siginfo info; - struct task_struct *task; -}; - /* location of GART table */ #define DRM_ATI_GART_MAIN 1 #define DRM_ATI_GART_FB 2 @@ -903,8 +896,6 @@ struct drm_device { wait_queue_head_t *vbl_queue; /**< VBLANK wait queue */ atomic_t *_vblank_count; /**< number of VBLANK interrupts (driver must alloc the right number of counters) */ spinlock_t vbl_lock; - struct list_head *vbl_sigs; /**< signal list to send on VBLANK */ - atomic_t vbl_signal_pending; /* number of signals pending on all crtcs*/ atomic_t *vblank_refcount; /* number of users of vblank interruptsper crtc */ u32 *last_vblank; /* protected by dev->vbl_lock, used */ /* for wraparound handling */ -- cgit v1.2.3 From 14d200c5e5bd19219d930bbb9a5a22758c8f5bec Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Fri, 6 Feb 2009 13:04:49 -0800 Subject: drm/i915: capture last_vblank count at IRQ uninstall time too MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In dc1336ff4fe08ae7cfe8301bfd7f0b2cfd31d20a (set vblank enable flag correctly across IRQ uninstall), we made sure drivers that uninstall their interrupt handler set the vblank enabled flag correctly, so that when interrupts are re-enabled, vblank interrupts & counts work as expected. However I missed the last_vblank field: it needs to be updated as well, otherwise, at the next drm_update_vblank_count we'll end up comparing a current count to a stale one (the last one captured by the disable function), which may trigger the wraparound handling, leading to a jumpy counter and hangs in drm_wait_vblank. The jumpy counter can prevent the DRM_WAIT_ON from returning success if the difference between the current count and the requested count is greater than 2^23, leading to timeouts or hangs, if the ioctl is restarted in a loop (as is the case in libdrm < 2.4.4). Signed-off-by: Jesse Barnes Acked-by: Michel Dänzer Tested-by: Timo Aaltonen Signed-off-by: Dave Airlie --- 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 69aa0ab28403..3795dbc0f50c 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -276,6 +276,7 @@ int drm_irq_uninstall(struct drm_device * dev) 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); -- cgit v1.2.3 From b3f5e7329df1a508ac58ebe7509fb7a47b9eab6a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 19 Feb 2009 14:48:22 +0000 Subject: drm: Correct unbalanced drm_vblank_put() during mode setting. The first time we install a mode, the vblank will be disabled for a pipe and so drm_vblank_get() in drm_vblank_pre_modeset() will fail. As we unconditionally call drm_vblank_put() afterwards, the vblank reference counter becomes unbalanced. Signed-off-by: Chris Wilson Acked-by: Jesse Barnes Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_irq.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 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 3795dbc0f50c..93e677a481f5 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -435,6 +435,8 @@ EXPORT_SYMBOL(drm_vblank_get); */ void drm_vblank_put(struct drm_device *dev, int crtc) { + BUG_ON (atomic_read (&dev->vblank_refcount[crtc]) == 0); + /* Last user schedules interrupt disable */ if (atomic_dec_and_test(&dev->vblank_refcount[crtc])) mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ); @@ -460,8 +462,9 @@ void drm_vblank_pre_modeset(struct drm_device *dev, int crtc) * so that interrupts remain enabled in the interim. */ if (!dev->vblank_inmodeset[crtc]) { - dev->vblank_inmodeset[crtc] = 1; - drm_vblank_get(dev, crtc); + dev->vblank_inmodeset[crtc] = 0x1; + if (drm_vblank_get(dev, crtc) == 0) + dev->vblank_inmodeset[crtc] |= 0x2; } } EXPORT_SYMBOL(drm_vblank_pre_modeset); @@ -473,9 +476,12 @@ void drm_vblank_post_modeset(struct drm_device *dev, int crtc) if (dev->vblank_inmodeset[crtc]) { spin_lock_irqsave(&dev->vbl_lock, irqflags); dev->vblank_disable_allowed = 1; - dev->vblank_inmodeset[crtc] = 0; spin_unlock_irqrestore(&dev->vbl_lock, irqflags); - drm_vblank_put(dev, crtc); + + if (dev->vblank_inmodeset[crtc] & 0x2) + drm_vblank_put(dev, crtc); + + dev->vblank_inmodeset[crtc] = 0; } } EXPORT_SYMBOL(drm_vblank_post_modeset); -- cgit v1.2.3