The old code generated an interrupt storm bad enough to completely take down my system.

Signed-off-by: Andy Lutomirski luto@mit.edu Cc: stable@kernel.org ---

Changes from v2: Don't use (wrong) #define'd register names.

drivers/gpu/drm/nouveau/nouveau_drv.h | 6 +++++ drivers/gpu/drm/nouveau/nouveau_irq.c | 1 + drivers/gpu/drm/nouveau/nv50_display.c | 35 +++++++++++++++++++++++-------- 3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h index b1be617..c926d88 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drv.h +++ b/drivers/gpu/drm/nouveau/nouveau_drv.h @@ -531,6 +531,12 @@ struct drm_nouveau_private { struct work_struct irq_work; struct work_struct hpd_work;

+ struct { + spinlock_t lock; + uint32_t hpd0_bits; + uint32_t hpd1_bits; + } hpd_state; + struct list_head vbl_waiting;

struct { diff --git a/drivers/gpu/drm/nouveau/nouveau_irq.c b/drivers/gpu/drm/nouveau/nouveau_irq.c index 794b0ee..b62a601 100644 --- a/drivers/gpu/drm/nouveau/nouveau_irq.c +++ b/drivers/gpu/drm/nouveau/nouveau_irq.c @@ -52,6 +52,7 @@ nouveau_irq_preinstall(struct drm_device *dev) if (dev_priv->card_type >= NV_50) { INIT_WORK(&dev_priv->irq_work, nv50_display_irq_handler_bh); INIT_WORK(&dev_priv->hpd_work, nv50_display_irq_hotplug_bh); + spin_lock_init(&dev_priv->hpd_state.lock); INIT_LIST_HEAD(&dev_priv->vbl_waiting); } } diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c index 612fa6d..d967cb6 100644 --- a/drivers/gpu/drm/nouveau/nv50_display.c +++ b/drivers/gpu/drm/nouveau/nv50_display.c @@ -1012,11 +1012,18 @@ nv50_display_irq_hotplug_bh(struct work_struct *work) struct drm_connector *connector; const uint32_t gpio_reg[4] = { 0xe104, 0xe108, 0xe280, 0xe284 }; uint32_t unplug_mask, plug_mask, change_mask; - uint32_t hpd0, hpd1 = 0; + uint32_t hpd0, hpd1;

- hpd0 = nv_rd32(dev, 0xe054) & nv_rd32(dev, 0xe050); + spin_lock_irq(&dev_priv->hpd_state.lock); + hpd0 = dev_priv->hpd_state.hpd0_bits; + dev_priv->hpd_state.hpd0_bits = 0; + hpd1 = dev_priv->hpd_state.hpd1_bits; + dev_priv->hpd_state.hpd1_bits = 0; + spin_unlock_irq(&dev_priv->hpd_state.lock); + + hpd0 &= nv_rd32(dev, 0xe050); if (dev_priv->chipset >= 0x90) - hpd1 = nv_rd32(dev, 0xe074) & nv_rd32(dev, 0xe070); + hpd1 &= nv_rd32(dev, 0xe070);

plug_mask = (hpd0 & 0x0000ffff) | (hpd1 << 16); unplug_mask = (hpd0 >> 16) | (hpd1 & 0xffff0000); @@ -1058,10 +1065,6 @@ nv50_display_irq_hotplug_bh(struct work_struct *work) helper->dpms(connector->encoder, DRM_MODE_DPMS_OFF); }

- nv_wr32(dev, 0xe054, nv_rd32(dev, 0xe054)); - if (dev_priv->chipset >= 0x90) - nv_wr32(dev, 0xe074, nv_rd32(dev, 0xe074)); - drm_helper_hpd_irq_event(dev); }

@@ -1072,8 +1075,22 @@ nv50_display_irq_handler(struct drm_device *dev) uint32_t delayed = 0;

if (nv_rd32(dev, NV50_PMC_INTR_0) & NV50_PMC_INTR_0_HOTPLUG) { - if (!work_pending(&dev_priv->hpd_work)) - queue_work(dev_priv->wq, &dev_priv->hpd_work); + uint32_t hpd0_bits, hpd1_bits = 0; + + hpd0_bits = nv_rd32(dev, 0xe054); + nv_wr32(dev, 0xe054, hpd0_bits); + + if (dev_priv->chipset >= 0x90) { + hpd1_bits = nv_rd32(dev, 0xe074); + nv_wr32(dev, 0xe074, hpd1_bits); + } + + spin_lock(&dev_priv->hpd_state.lock); + dev_priv->hpd_state.hpd0_bits |= hpd0_bits; + dev_priv->hpd_state.hpd1_bits |= hpd1_bits; + spin_unlock(&dev_priv->hpd_state.lock); + + queue_work(dev_priv->wq, &dev_priv->hpd_work); }

while (nv_rd32(dev, NV50_PMC_INTR_0) & NV50_PMC_INTR_0_DISPLAY) {