diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index e7411f363b3d..3843383e13cc 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -641,6 +641,7 @@ typedef struct drm_i915_private { struct intel_gmbus gmbus[GMBUS_NUM_PORTS]; + /** gmbus_mutex protects against concurrent usage of the single hw gmbus * controller on different i2c buses. */ struct mutex gmbus_mutex; @@ -650,6 +651,8 @@ typedef struct drm_i915_private { */ uint32_t gpio_mmio_base; + wait_queue_head_t gmbus_wait_queue; + struct pci_dev *bridge_dev; struct intel_ring_buffer ring[I915_NUM_RINGS]; uint32_t next_seqno; diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 956b95f1f113..917a48de08fa 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -527,7 +527,11 @@ static void gen6_queue_rps_work(struct drm_i915_private *dev_priv, static void gmbus_irq_handler(struct drm_device *dev) { + struct drm_i915_private *dev_priv = (drm_i915_private_t *) dev->dev_private; + DRM_DEBUG_DRIVER("GMBUS interrupt\n"); + + wake_up_all(&dev_priv->gmbus_wait_queue); } static irqreturn_t valleyview_irq_handler(int irq, void *arg) diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index a16eecdf1ed1..8b7189253cb4 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -63,6 +63,7 @@ intel_i2c_reset(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0); + I915_WRITE(dev_priv->gpio_mmio_base + GMBUS4, 0); } static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable) @@ -204,20 +205,38 @@ intel_gpio_setup(struct intel_gmbus *bus, u32 pin) static int gmbus_wait_hw_status(struct drm_i915_private *dev_priv, - u32 gmbus2_status) + u32 gmbus2_status, + u32 gmbus4_irq_en) { - int ret; + int i; int reg_offset = dev_priv->gpio_mmio_base; - u32 gmbus2; + u32 gmbus2 = 0; + DEFINE_WAIT(wait); - ret = wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) & - (GMBUS_SATOER | gmbus2_status), - 50); + /* Important: The hw handles only the first bit, so set only one! Since + * we also need to check for NAKs besides the hw ready/idle signal, we + * need to wake up periodically and check that ourselves. */ + I915_WRITE(GMBUS4 + reg_offset, gmbus4_irq_en); + + for (i = 0; i < msecs_to_jiffies(50) + 1; i++) { + prepare_to_wait(&dev_priv->gmbus_wait_queue, &wait, + TASK_UNINTERRUPTIBLE); + + gmbus2 = I915_READ(GMBUS2 + reg_offset); + if (gmbus2 & (GMBUS_SATOER | gmbus2_status)) + break; + + schedule_timeout(1); + } + finish_wait(&dev_priv->gmbus_wait_queue, &wait); + + I915_WRITE(GMBUS4 + reg_offset, 0); if (gmbus2 & GMBUS_SATOER) return -ENXIO; - - return ret; + if (gmbus2 & gmbus2_status) + return 0; + return -ETIMEDOUT; } static int @@ -238,7 +257,8 @@ gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg, int ret; u32 val, loop = 0; - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY); + ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY, + GMBUS_HW_RDY_EN); if (ret) return ret; @@ -282,7 +302,8 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg) I915_WRITE(GMBUS3 + reg_offset, val); - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY); + ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_RDY, + GMBUS_HW_RDY_EN); if (ret) return ret; } @@ -367,7 +388,8 @@ gmbus_xfer(struct i2c_adapter *adapter, if (ret == -ENXIO) goto clear_err; - ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_WAIT_PHASE); + ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_WAIT_PHASE, + GMBUS_HW_WAIT_EN); if (ret == -ENXIO) goto clear_err; if (ret) @@ -473,6 +495,7 @@ int intel_setup_gmbus(struct drm_device *dev) dev_priv->gpio_mmio_base = 0; mutex_init(&dev_priv->gmbus_mutex); + init_waitqueue_head(&dev_priv->gmbus_wait_queue); for (i = 0; i < GMBUS_NUM_PORTS; i++) { struct intel_gmbus *bus = &dev_priv->gmbus[i];