Re: [PATCH v2 1/3] drm/i915/hda: Add audio component stub

Takashi Iwai
2016-05-13T07:48:16Z

On Thu, 12 May 2016 20:06:53 +0200,
Imre Deak wrote:
>
> 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.
>
> v2:
> - Fail the probe in case component registration fails, instead of
> suppressing the error. (Ville)
> - Register the component only for the real PCI device function.
>
> CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>

I haven't received v2 for the rest two patches. I suppose they are
unchanged from v1?

It'd be good if we can get this into 4.7. Will this go through drm
tree, or my tree? I don't mind either way. If you merge this do
drm(-intel) tree, just let me know the stable git id so that I can
merge it to sound.git tree with my rest two patches.

thanks,

Takashi

> ---
> drivers/gpu/drm/i915/i915_drv.c | 51 +++++++++++++++++++++++-------------
> drivers/gpu/drm/i915/intel_audio.c | 53 ++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_drv.h | 2 ++
> include/drm/i915_component.h | 5 ++++
> 4 files changed, 93 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 5ae7960..b127810 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1016,12 +1016,6 @@ 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 (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");
> - return -ENODEV;
> - }
> -
> /* Only bind to function 0 of the device. Early generations
> * used function 1 as a placeholder for multi-head. This causes
> * us confusion instead, especially on the systems where both
> @@ -1030,6 +1024,29 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (PCI_FUNC(pdev->devfn))
> return -ENODEV;
>
> + if (!(driver.driver_features & DRIVER_MODESET)) {
> + int ret;
> +
> + /*
> + * Notify the HDA driver so that it doesn't block waiting for
> + * i915 to become ready.
> + */
> + ret = i915_audio_component_stub_init(&pdev->dev);
> + if (ret)
> + return ret;
> +
> + /* 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");
> + return -ENODEV;
> + }
> +
> /*
> * apple-gmux is needed on dual GPU MacBook Pro
> * to probe the panel if we're the inactive GPU.
> @@ -1045,8 +1062,15 @@ 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);
> }
>
> @@ -1767,24 +1791,15 @@ static int __init i915_init(void)
> if (vgacon_text_force() && i915.modeset == -1)
> driver.driver_features &= ~DRIVER_MODESET;
>
> - 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 b9329c2..603b3fe 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -824,3 +824,56 @@ 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,
> +};
> +
> +int 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 ret;
> +}
> +
> +void i915_audio_component_stub_cleanup(struct device *dev)
> +{
> + component_del(dev, &i915_audio_component_stub_bind_ops);
> +}
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 0a9c10d..a828e00 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1111,6 +1111,8 @@ 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);
> +int i915_audio_component_stub_init(struct device *dev);
> +void i915_audio_component_stub_cleanup(struct device *dev);
>
> /* intel_display.c */
> void intel_update_rawclk(struct drm_i915_private *dev_priv);
> diff --git a/include/drm/i915_component.h b/include/drm/i915_component.h
> index b46fa0e..33da85a 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.
> --
> 2.5.0