[PATCH v4 1/6] drm: add SimpleDRM driver

[Tom Gundersen]

Hi David,

On Sun, Sep 1, 2013 at 3:36 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
> 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 one dumb-buffer and attach it to the CRTC. Only if
> the buffer is destroyed, a new buffer can be created. The buffer is
> directly mapped into user-space, so we have only resources for a single
> buffer. Otherwise, shadow buffers plus damage-request would be needed.
>
> Signed-off-by: David Herrmann <dh.herrmann at gmail.com>
> Tested-by: Stephen Warren <swarren at nvidia.com>
> ---

[...]

> +static int sdrm_conn_fill_modes(struct drm_connector *conn, uint32_t max_x,
> +                               uint32_t max_y)
> +{
> +       struct sdrm_device *sdrm = conn->dev->dev_private;
> +       struct drm_display_mode *mode;
> +       int ret;
> +
> +       if (conn->force == DRM_FORCE_ON)
> +               conn->status = connector_status_connected;
> +       else if (conn->force)
> +               conn->status = connector_status_disconnected;
> +       else
> +               conn->status = connector_status_connected;
> +
> +       list_for_each_entry(mode, &conn->modes, head)
> +               mode->status = MODE_UNVERIFIED;
> +
> +       mode = drm_gtf_mode(sdrm->ddev, sdrm->fb_width, sdrm->fb_height,
> +                           60, 0, 0);
> +       if (mode) {
> +               mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> +               drm_mode_probed_add(conn, mode);
> +               sdrm->mode = mode;

Should you also be setting sdrm->fb_{width,height} to
mode->{v,h}display here? Otherwise, due to the rounding in
drm_gtf_mode(), these values won't necessarily match (which I suppose
they must?).

Cheers,

Tom