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path: root/drivers/gpu/drm/i915/intel_i2c.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index acf8aec9ada..639fe192997 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -203,7 +203,13 @@ intel_gpio_setup(struct intel_gmbus *bus, u32 pin)
algo->data = bus;
}
-#define HAS_GMBUS_IRQ(dev) (INTEL_INFO(dev)->gen >= 4)
+/*
+ * gmbus on gen4 seems to be able to generate legacy interrupts even when in MSI
+ * mode. This results in spurious interrupt warnings if the legacy irq no. is
+ * shared with another device. The kernel then disables that interrupt source
+ * and so prevents the other device from working properly.
+ */
+#define HAS_GMBUS_IRQ(dev) (INTEL_INFO(dev)->gen >= 5)
static int
gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
u32 gmbus2_status,
@@ -214,12 +220,15 @@ gmbus_wait_hw_status(struct drm_i915_private *dev_priv,
u32 gmbus2 = 0;
DEFINE_WAIT(wait);
+ if (!HAS_GMBUS_IRQ(dev_priv->dev))
+ gmbus4_irq_en = 0;
+
/* 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++) {
+ for (i = 0; i < msecs_to_jiffies_timeout(50); i++) {
prepare_to_wait(&dev_priv->gmbus_wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
@@ -254,7 +263,8 @@ gmbus_wait_idle(struct drm_i915_private *dev_priv)
/* Important: The hw handles only the first bit, so set only one! */
I915_WRITE(GMBUS4 + reg_offset, GMBUS_IDLE_EN);
- ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C, 10);
+ ret = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
+ msecs_to_jiffies_timeout(10));
I915_WRITE(GMBUS4 + reg_offset, 0);
@@ -513,7 +523,9 @@ int intel_setup_gmbus(struct drm_device *dev)
struct drm_i915_private *dev_priv = dev->dev_private;
int ret, i;
- if (HAS_PCH_SPLIT(dev))
+ if (HAS_PCH_NOP(dev))
+ return 0;
+ else if (HAS_PCH_SPLIT(dev))
dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
else if (IS_VALLEYVIEW(dev))
dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE;