drm: dw-hdmi: Implement the mode_fixup drm helper
authorRomain Perier <romain.perier@collabora.com>
Fri, 7 Apr 2017 12:17:43 +0000 (14:17 +0200)
committerArchit Taneja <architt@codeaurora.org>
Mon, 10 Apr 2017 09:23:10 +0000 (14:53 +0530)
This helper is supposed to validate or reject the modeline before it
applied by the mode setting. Currently this function has been dropped,
it was previously set to a dummy function that always returned true. For
both cases, this means that userspace can ask for a bad modeline that
will be always accepted.

On some platforms, like Rockchip, the drm dw_hdmi-rockchip variant driver
already implements the atomic_check drm helper, so mode_fixup cannot be
handled and implemented there (as drm_atomic_helper relies on either
atomic_check or mode_fixup).

This commit implements this helper. It only checks that this mode is
correct from the connector point of view.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407121743.4142-1-romain.perier@collabora.com
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

index 3bc856cc6daa633462f04ebce1476461d6c550e0..4e1f54a675d8def6c5f3f2ae8e261d802c17ccb2 100644 (file)
@@ -1947,6 +1947,20 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
        return 0;
 }
 
+static bool dw_hdmi_bridge_mode_fixup(struct drm_bridge *bridge,
+                                     const struct drm_display_mode *orig_mode,
+                                     struct drm_display_mode *mode)
+{
+       struct dw_hdmi *hdmi = bridge->driver_private;
+       struct drm_connector *connector = &hdmi->connector;
+       enum drm_mode_status status;
+
+       status = dw_hdmi_connector_mode_valid(connector, mode);
+       if (status != MODE_OK)
+               return false;
+       return true;
+}
+
 static void dw_hdmi_bridge_mode_set(struct drm_bridge *bridge,
                                    struct drm_display_mode *orig_mode,
                                    struct drm_display_mode *mode)
@@ -1988,6 +2002,7 @@ static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
        .enable = dw_hdmi_bridge_enable,
        .disable = dw_hdmi_bridge_disable,
        .mode_set = dw_hdmi_bridge_mode_set,
+       .mode_fixup = dw_hdmi_bridge_mode_fixup,
 };
 
 static irqreturn_t dw_hdmi_i2c_irq(struct dw_hdmi *hdmi)