[PATCH 1/3] drm/i915/hda: Add audio component stub

Takashi Iwai
2016-04-07T10:57:31Z

From: Imre Deak <imre.deak@intel.com>

User may pass nomodeset or i915.modeset=0 option to disable i915 KMS
explicitly. Although this itself works fine, it breaks the weak
dependency the HD-audio driver requires, and it's the reason the
delayed component binding isn't implemented in HD-audio. Since i915
doesn't notify its disablement, HD-audio would be blocked
unnecessarily endlessly, waiting for the bind with i915.

This patch introduces a stub audio component binding when i915 driver
is loaded with KMS off like the boot options above. Then i915 driver
still registers the slave component but with the new "disabled" ops
flag, so that the master component (HD-audio) can know clearly the
slave state.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_drv.c | 34 +++++++++++++--------
drivers/gpu/drm/i915/intel_audio.c | 61 ++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_drv.h | 2 ++
include/drm/i915_component.h | 5 ++++
4 files changed, 90 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 20e82008b8b6..21c6bac5468e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -950,6 +950,19 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
struct intel_device_info *intel_info =
(struct intel_device_info *) ent->driver_data;

+ if (!(driver.driver_features & DRIVER_MODESET)) {
+ /*
+ * Notify the HDA driver so that it doesn't block waiting for
+ * i915 to become ready.
+ */
+ i915_audio_component_stub_init(&pdev->dev);
+
+ /* Silently fail loading to not upset userspace. */
+ DRM_DEBUG_DRIVER("KMS and UMS disabled.\n");
+
+ return 0;
+ }
+
if (IS_PRELIMINARY_HW(intel_info) && !i915.preliminary_hw_support) {
DRM_INFO("This hardware requires preliminary hardware support.\n"
"See CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT, and/or modparam preliminary_hw_support\n");
@@ -979,8 +992,14 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
static void
i915_pci_remove(struct pci_dev *pdev)
{
- struct drm_device *dev = pci_get_drvdata(pdev);
+ struct drm_device *dev;

+ if (!(driver.driver_features & DRIVER_MODESET)) {
+ i915_audio_component_stub_cleanup(&pdev->dev);
+ return;
+ }
+
+ dev = pci_get_drvdata(pdev);
drm_put_dev(dev);
}

@@ -1747,24 +1766,15 @@ static int __init i915_init(void)
driver.driver_features &= ~DRIVER_MODESET;
#endif

- if (!(driver.driver_features & DRIVER_MODESET)) {
- /* Silently fail loading to not upset userspace. */
- DRM_DEBUG_DRIVER("KMS and UMS disabled.\n");
- return 0;
- }
-
if (i915.nuclear_pageflip)
driver.driver_features |= DRIVER_ATOMIC;

- return drm_pci_init(&driver, &i915_pci_driver);
+ return pci_register_driver(&i915_pci_driver);
}

static void __exit i915_exit(void)
{
- if (!(driver.driver_features & DRIVER_MODESET))
- return; /* Never loaded a driver. */
-
- drm_pci_exit(&driver, &i915_pci_driver);
+ pci_unregister_driver(&i915_pci_driver);
}

module_init(i915_init);
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 30f921421b0c..bd9e9760903a 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -835,3 +835,64 @@ void i915_audio_component_cleanup(struct drm_i915_private *dev_priv)
component_del(dev_priv->dev->dev, &i915_audio_component_bind_ops);
dev_priv->audio_component_registered = false;
}
+
+static const struct i915_audio_component_ops i915_audio_component_stub_ops = {
+ .owner = THIS_MODULE,
+ .disabled = true,
+};
+
+static int i915_audio_component_stub_bind(struct device *i915_stub_dev,
+ struct device *hda_dev, void *data)
+{
+ struct i915_audio_component *acomp = data;
+
+ if (WARN_ON(acomp->ops || acomp->dev))
+ return -EEXIST;
+
+ acomp->ops = &i915_audio_component_stub_ops;
+ acomp->dev = i915_stub_dev;
+
+ return 0;
+}
+
+static void i915_audio_component_stub_unbind(struct device *i915_stub_dev,
+ struct device *hda_dev, void *data)
+{
+ struct i915_audio_component *acomp = data;
+
+ acomp->ops = NULL;
+ acomp->dev = NULL;
+}
+
+static const struct component_ops i915_audio_component_stub_bind_ops = {
+ .bind = i915_audio_component_stub_bind,
+ .unbind = i915_audio_component_stub_unbind,
+};
+
+static const struct file_operations component_stub_dev_ops = {
+ .owner = THIS_MODULE,
+};
+
+static bool i915_audio_component_stub_registered;
+
+void i915_audio_component_stub_init(struct device *dev)
+{
+ int ret;
+
+ ret = component_add(dev, &i915_audio_component_stub_bind_ops);
+ if (ret < 0) {
+ DRM_ERROR("failed to add audio stub component (%d)\n", ret);
+ return;
+ }
+
+ i915_audio_component_stub_registered = true;
+}
+
+void i915_audio_component_stub_cleanup(struct device *dev)
+{
+ if (!i915_audio_component_stub_registered)
+ return;
+
+ component_del(dev, &i915_audio_component_stub_bind_ops);
+ i915_audio_component_stub_registered = false;
+}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4c027d69fac9..e1d9c33b113e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1056,6 +1056,8 @@ void intel_audio_codec_enable(struct intel_encoder *encoder);
void intel_audio_codec_disable(struct intel_encoder *encoder);
void i915_audio_component_init(struct drm_i915_private *dev_priv);
void i915_audio_component_cleanup(struct drm_i915_private *dev_priv);
+void i915_audio_component_stub_init(struct device *dev);
+void i915_audio_component_stub_cleanup(struct device *dev);

/* intel_display.c */
extern const struct drm_plane_funcs intel_plane_funcs;
diff --git a/include/drm/i915_component.h b/include/drm/i915_component.h
index b46fa0ef3005..33da85aa70c3 100644
--- a/include/drm/i915_component.h
+++ b/include/drm/i915_component.h
@@ -39,6 +39,11 @@ struct i915_audio_component_ops {
*/
struct module *owner;
/**
+ * @disabled: i915 driver loaded with modeset=0, the services provided
+ * via the audio component interface are not available.
+ */
+ bool disabled;
+ /**
* @get_power: get the POWER_DOMAIN_AUDIO power well
*
* Request the power well to be turned on.
--
2.8.1