diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panel.c')
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 38 |
1 files changed, 31 insertions, 7 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index e814020bbcd3..9940e96d35e3 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -24,6 +24,7 @@ #include <linux/backlight.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/of.h> #include <drm/drm_crtc.h> #include <drm/drm_panel.h> @@ -161,6 +162,15 @@ int drm_panel_unprepare(struct drm_panel *panel) if (!panel) return -EINVAL; + /* + * If you are seeing the warning below it likely means one of two things: + * - Your panel driver incorrectly calls drm_panel_unprepare() in its + * shutdown routine. You should delete this. + * - You are using panel-edp or panel-simple and your DRM modeset + * driver's shutdown() callback happened after the panel's shutdown(). + * In this case the warning is harmless though ideally you should + * figure out how to reverse the order of the shutdown() callbacks. + */ if (!panel->prepared) { dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); return 0; @@ -245,6 +255,15 @@ int drm_panel_disable(struct drm_panel *panel) if (!panel) return -EINVAL; + /* + * If you are seeing the warning below it likely means one of two things: + * - Your panel driver incorrectly calls drm_panel_disable() in its + * shutdown routine. You should delete this. + * - You are using panel-edp or panel-simple and your DRM modeset + * driver's shutdown() callback happened after the panel's shutdown(). + * In this case the warning is harmless though ideally you should + * figure out how to reverse the order of the shutdown() callbacks. + */ if (!panel->enabled) { dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); return 0; @@ -274,19 +293,24 @@ EXPORT_SYMBOL(drm_panel_disable); * The modes probed from the panel are automatically added to the connector * that the panel is attached to. * - * Return: The number of modes available from the panel on success or a - * negative error code on failure. + * Return: The number of modes available from the panel on success, or 0 on + * failure (no modes). */ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector) { if (!panel) - return -EINVAL; + return 0; + + if (panel->funcs && panel->funcs->get_modes) { + int num; - if (panel->funcs && panel->funcs->get_modes) - return panel->funcs->get_modes(panel, connector); + num = panel->funcs->get_modes(panel, connector); + if (num > 0) + return num; + } - return -EOPNOTSUPP; + return 0; } EXPORT_SYMBOL(drm_panel_get_modes); @@ -390,7 +414,7 @@ bool drm_is_panel_follower(struct device *dev) * don't bother trying to parse it here. We just need to know if the * property is there. */ - return of_property_read_bool(dev->of_node, "panel"); + return of_property_present(dev->of_node, "panel"); } EXPORT_SYMBOL(drm_is_panel_follower); |