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

Daniel Vetter
2016-10-25T06:46:45Z

On Tue, Oct 25, 2016 at 08:44:22AM +0200, Daniel Vetter wrote:
> 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);

Oh and you might want to look into drm_dev_init, allows you to use
subclassing instead of pointer chasing for your driver-private data.
-Daniel

> > + 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
> http://blog.ffwll.ch

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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