From a7d85a90615128cd35aa341990485181fd361e50 Mon Sep 17 00:00:00 2001 From: kettenis Date: Thu, 13 Sep 2018 09:32:27 +0000 Subject: [PATCH] In drm_wait_one_vblank() add a delay when we're "cold". Interrupts aren't enabled at that point, so we cannot wait for one to happen. But having no delay at all breaks detection of some output connectors. Thanks to Philippe Meunier for tracking down the issue. ok millert@, jsg@ --- sys/dev/pci/drm/drm_irq.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/sys/dev/pci/drm/drm_irq.c b/sys/dev/pci/drm/drm_irq.c index dd8474fc4a0..cbb80424abc 100644 --- a/sys/dev/pci/drm/drm_irq.c +++ b/sys/dev/pci/drm/drm_irq.c @@ -1317,8 +1317,21 @@ void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe) int ret; u32 last; - if (WARN_ON(pipe >= dev->num_crtcs) || cold) + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + +#ifdef __OpenBSD__ + /* + * If we're cold, vblank interrupts won't happen even if + * they're turned on by the driver. Just stall long enough + * for a vblank to pass. This assumes a vrefresh of at least + * 25 Hz. + */ + if (cold) { + delay(40000); return; + } +#endif ret = drm_vblank_get(dev, pipe); if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret)) -- 2.20.1