From: Eric Anholt Date: Wed, 28 Jan 2009 05:19:41 +0000 (-0800) Subject: drm: Rip out the racy, unused vblank signal code. X-Git-Tag: v2.6.29-rc3~4 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?p=linux-2.6-omap-h63xx.git;a=commitdiff_plain;h=30b23634084d95781f7611c0713cb551a0c0a152 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 --- diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 477caa1b1e4..69aa0ab2840 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 32e5096554e..8e77357334a 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 afb7858c068..8190b9bcc2d 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 */