Re: [Intel-gfx] [PATCH 2/4] drm/i915: Initialize fbdev DRM client with callback functions

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 28 Mar 2023, Thomas Zimmermann <tzimmermann@suse.de> wrote:
> Initialize i915's fbdev client by giving an instance of struct
> drm_client_funcsi to drm_client_init(). Also clean up with
> drm_client_release().
>
> Doing this in i915 prevents fbdev helpers from initializing and
> releasing the client internally (see drm_fb_helper_init()). No
> functional change yet; the client callbacks will be filled later.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/i915/display/intel_fbdev.c | 43 ++++++++++++++++++++--
>  1 file changed, 39 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 88de79279ce5..290da5e94bc5 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -364,6 +364,7 @@ static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)
>  	if (ifbdev->fb)
>  		drm_framebuffer_remove(&ifbdev->fb->base);
>  
> +	drm_client_release(&ifbdev->helper.client);
>  	drm_fb_helper_unprepare(&ifbdev->helper);
>  	kfree(ifbdev);
>  }
> @@ -656,6 +657,30 @@ void intel_fbdev_restore_mode(struct drm_i915_private *dev_priv)
>  		intel_fbdev_invalidate(ifbdev);
>  }
>  
> +/*
> + * Fbdev client and struct drm_client_funcs
> + */
> +
> +static void intel_fbdev_client_unregister(struct drm_client_dev *client)
> +{ }
> +
> +static int intel_fbdev_client_restore(struct drm_client_dev *client)
> +{
> +	return 0;
> +}
> +
> +static int intel_fbdev_client_hotplug(struct drm_client_dev *client)
> +{
> +	return 0;
> +}
> +
> +static const struct drm_client_funcs intel_fbdev_client_funcs = {
> +	.owner		= THIS_MODULE,
> +	.unregister	= intel_fbdev_client_unregister,
> +	.restore	= intel_fbdev_client_restore,
> +	.hotplug	= intel_fbdev_client_hotplug,
> +};
> +
>  int intel_fbdev_init(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> @@ -677,16 +702,26 @@ int intel_fbdev_init(struct drm_device *dev)
>  	else
>  		ifbdev->preferred_bpp = ifbdev->helper.preferred_bpp;
>  
> +	ret = drm_client_init(dev, &ifbdev->helper.client, "i915-fbdev",
> +			      &intel_fbdev_client_funcs);
> +	if (ret)
> +		goto err_drm_fb_helper_unprepare;
> +
>  	ret = drm_fb_helper_init(dev, &ifbdev->helper);
> -	if (ret) {
> -		kfree(ifbdev);
> -		return ret;
> -	}
> +	if (ret)
> +		goto err_drm_client_release;
>  
>  	dev_priv->display.fbdev.fbdev = ifbdev;
>  	INIT_WORK(&dev_priv->display.fbdev.suspend_work, intel_fbdev_suspend_worker);
>  
>  	return 0;
> +
> +err_drm_client_release:
> +	drm_client_release(&ifbdev->helper.client);
> +err_drm_fb_helper_unprepare:
> +	drm_client_release(&ifbdev->helper.client);

I suppose this should be

drm_fb_helper_unprepare(&ifbdev->helper);

instead of the double drm_client_release(). And we're missing this
cleanup already.

BR,
Jani.


> +	kfree(ifbdev);
> +	return ret;
>  }
>  
>  static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)

-- 
Jani Nikula, Intel Open Source Graphics Center