[PATCH 3/4] drm/omap: Make fixed resolution panels work

[Rob Clark]

On Tue, Mar 5, 2013 at 9:17 AM, Archit Taneja <archit at ti.com> wrote:
> The omapdrm driver requires omapdss panel drivers to expose ops like detect,
> set_timings and check_timings. These can be NULL for fixed panel DPI, DBI, DSI
> and SDI drivers. At some places, there are no checks to see if the panel driver
> has these ops or not, and that leads to a crash.
>
> The following things are done to make fixed panels work:
>
> - The omap_connector's detect function is modified such that it considers panel
>   types which are generally fixed panels as always connected(provided the panel
>   driver doesn't have a detect op). Hence, the connector corresponding to these
>   panels is always in a 'connected' state.
>
> - If a panel driver doesn't have a check_timings op, assume that it supports the
>   mode passed to omap_connector_mode_valid(the 'mode_valid' drm helper function)
>
> - The function omap_encoder_update shouldn't really do anything for fixed
>   resolution panels, make sure that it calls set_timings only if the panel
>   driver has one.
>
> Signed-off-by: Archit Taneja <archit at ti.com>
> ---
>  drivers/gpu/drm/omapdrm/omap_connector.c |   10 ++++++++--
>  drivers/gpu/drm/omapdrm/omap_encoder.c   |    6 ++++--
>  2 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
> index c451c41..c952324 100644
> --- a/drivers/gpu/drm/omapdrm/omap_connector.c
> +++ b/drivers/gpu/drm/omapdrm/omap_connector.c
> @@ -110,6 +110,11 @@ static enum drm_connector_status omap_connector_detect(
>                         ret = connector_status_connected;
>                 else
>                         ret = connector_status_disconnected;
> +       } else if (dssdev->type == OMAP_DISPLAY_TYPE_DPI ||
> +                       dssdev->type == OMAP_DISPLAY_TYPE_DBI ||
> +                       dssdev->type == OMAP_DISPLAY_TYPE_SDI ||
> +                       dssdev->type == OMAP_DISPLAY_TYPE_DSI) {
> +               ret = connector_status_connected;
>         } else {
>                 ret = connector_status_unknown;
>         }
> @@ -189,12 +194,13 @@ static int omap_connector_mode_valid(struct drm_connector *connector,
>         struct omap_video_timings timings = {0};
>         struct drm_device *dev = connector->dev;
>         struct drm_display_mode *new_mode;
> -       int ret = MODE_BAD;
> +       int r, ret = MODE_BAD;
>
>         copy_timings_drm_to_omap(&timings, mode);
>         mode->vrefresh = drm_mode_vrefresh(mode);
>
> -       if (!dssdrv->check_timings(dssdev, &timings)) {
> +       r = dssdrv->check_timings ? dssdrv->check_timings(dssdev, &timings) : 0;
> +       if (!r) {
>                 /* check if vrefresh is still valid */
>                 new_mode = drm_mode_duplicate(dev, mode);
>                 new_mode->clock = timings.pixel_clock;
> diff --git a/drivers/gpu/drm/omapdrm/omap_encoder.c b/drivers/gpu/drm/omapdrm/omap_encoder.c
> index d48df71..9aed178 100644
> --- a/drivers/gpu/drm/omapdrm/omap_encoder.c
> +++ b/drivers/gpu/drm/omapdrm/omap_encoder.c
> @@ -135,13 +135,15 @@ int omap_encoder_update(struct drm_encoder *encoder,
>
>         dssdev->output->manager = mgr;
>
> -       ret = dssdrv->check_timings(dssdev, timings);
> +       ret = dssdrv->check_timings ?
> +               dssdrv->check_timings(dssdev, timings) : 0;
>         if (ret) {
>                 dev_err(dev->dev, "could not set timings: %d\n", ret);
>                 return ret;
>         }
>
> -       dssdrv->set_timings(dssdev, timings);
> +       if (dssdrv->set_timings)
> +               dssdrv->set_timings(dssdev, timings);

maybe either here or _mode_valid(), for panels that don't have
set_timings(), we should double check that the new timings match what
we get from the panel's get_timings().  Other than that, it looks
fine.

BR,
-R

>         return 0;
>  }
> --
> 1.7.10.4
>