[PATCH v5 6/7] drm: add SimpleDRM driver

[Noralf Trønnes]

Den 02.09.2016 10:22, skrev David Herrmann:
> The SimpleDRM driver binds to simple-framebuffer devices and provides a
> DRM/KMS API. It provides only a single CRTC+encoder+connector combination
> plus one initial mode.
>
> Userspace can create dumb-buffers which can be blit into the real
> framebuffer similar to UDL. No access to the real framebuffer is allowed
> (compared to earlier version of this driver) to avoid security issues.
> Furthermore, this way we can support arbitrary modes as long as we have a
> conversion-helper.
>
> Signed-off-by: David Herrmann <dh.herrmann at gmail.com>
> ---

[...]

> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c

[...]

> +static int sdrm_fop_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> +	struct drm_file *dfile = file->private_data;
> +	struct drm_device *dev = dfile->minor->dev;
> +	struct drm_gem_object *obj = NULL;
> +	struct drm_vma_offset_node *node;
> +	int r;
> +
> +	drm_vma_offset_lock_lookup(dev->vma_offset_manager);
> +	node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
> +						  vma->vm_pgoff,
> +						  vma_pages(vma));
> +	if (likely(node)) {
> +		obj = container_of(node, struct drm_gem_object, vma_node);
> +		if (!kref_get_unless_zero(&obj->refcount))
> +			obj = NULL;
> +	}
> +	drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
> +
> +	if (!obj)
> +		return -EINVAL;
> +
> +	if (!drm_vma_node_is_allowed(node, dfile)) {

I get:
drivers/gpu/drm/simpledrm/simpledrm_drv.c:320:2: warning: passing 
argument 2 of ‘drm_vma_node_is_allowed’ from incompatible pointer type 
[enabled by default]

dfile -> file

> +		drm_gem_object_unreference_unlocked(obj);
> +		return -EACCES;
> +	}
> +
> +	if (vma->vm_file)
> +		fput(vma->vm_file);
> +	vma->vm_file = get_file(obj->filp);
> +	vma->vm_pgoff = 0;
> +
> +	r = obj->filp->f_op->mmap(obj->filp, vma);
> +	drm_gem_object_unreference_unlocked(obj);
> +	return r;
> +}

[...]

> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_kms.c b/drivers/gpu/drm/simpledrm/simpledrm_kms.c

[...]

> +static void sdrm_crtc_send_vblank_event(struct drm_crtc *crtc)
> +{
> +	if (crtc->state && crtc->state->event) {
> +		spin_lock_irq(&crtc->dev->event_lock);
> +		drm_crtc_send_vblank_event(crtc, crtc->state->event);
> +		spin_unlock_irq(&crtc->dev->event_lock);
> +		crtc->state->event = NULL;
> +	}
> +}
> +
> +void sdrm_display_pipe_update(struct drm_simple_display_pipe *pipe,
> +			      struct drm_plane_state *plane_state)
> +{
> +	struct drm_framebuffer *dfb = pipe->plane.state->fb;
> +	struct sdrm_fb *fb;
> +
> +	sdrm_crtc_send_vblank_event(&pipe->crtc);
> +
> +	if (dfb) {
> +		fb = container_of(dfb, struct sdrm_fb, base);
> +		pipe->plane.fb = dfb;
> +		sdrm_dirty(fb, 0, 0, dfb->width, dfb->height);
> +	}
> +}
> +
> +static void sdrm_display_pipe_enable(struct drm_simple_display_pipe *pipe,
> +				     struct drm_crtc_state *crtc_state)
> +{
> +	sdrm_crtc_send_vblank_event(&pipe->crtc);
> +}
> +
> +static void sdrm_display_pipe_disable(struct drm_simple_display_pipe *pipe)
> +{
> +	sdrm_crtc_send_vblank_event(&pipe->crtc);
> +}
> +
> +static const struct drm_simple_display_pipe_funcs sdrm_pipe_funcs = {
> +	.update		= sdrm_display_pipe_update,
> +	.enable		= sdrm_display_pipe_enable,
> +	.disable	= sdrm_display_pipe_disable,
> +};

The enable and disable callbacks can be removed.
This commit in drm-misc fixed the flip done timeout:
drm/simple-helpers: Always add planes to the state update


Noralf.