Re: [PATCH v5 1/7] drm: sunxi: Add a basic DRM driver for Allwinner DE2

Daniel Vetter
2016-10-25T06:44:22Z

On Fri, Oct 21, 2016 at 09:26:18AM +0200, Jean-Francois Moine wrote:
> +static int de2_drm_bind(struct device *dev)
> +{
> + struct drm_device *drm;
> + struct priv *priv;
> + int ret;
> +
> + drm = drm_dev_alloc(&de2_drm_driver, dev);
> + if (!drm)
> + return -ENOMEM;
> +
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + dev_err(dev, "failed to allocate private area\n");
> + ret = -ENOMEM;
> + goto out1;
> + }
> +
> + dev_set_drvdata(dev, drm);
> + drm->dev_private = priv;
> +
> + drm_mode_config_init(drm);
> + drm->mode_config.min_width = 32; /* needed for cursor */
> + drm->mode_config.min_height = 32;
> + drm->mode_config.max_width = 1920;
> + drm->mode_config.max_height = 1080;
> + drm->mode_config.funcs = &de2_mode_config_funcs;
> +
> + drm->irq_enabled = true;
> +
> + /* initialize the display engine */
> + priv->soc_type = (int) of_match_device(de2_drm_of_match, dev)->data;
> + ret = de2_de_init(priv, dev);
> + if (ret)
> + goto out2;
> +
> + /* start the subdevices */
> + ret = component_bind_all(dev, drm);
> + if (ret < 0)
> + goto out2;
> +
> + ret = drm_dev_register(drm, 0);

This needs to be the very last step in your driver load sequence.
Kerneldoc explains why. Similar, but inverted for unloading:
drm_dev_unregister is the very first thing you must call.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation