diff options
| -rw-r--r-- | Documentation/gpu/todo.rst | 24 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 49 | ||||
| -rw-r--r-- | include/drm/drm_panel.h | 14 |
3 files changed, 81 insertions, 6 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 02de2ff6b84f..aa0052f9b93b 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -460,6 +460,30 @@ Contact: Thomas Zimmermann <tzimmermann@suse.de> Level: Starter +Clean up checks for already prepared/enabled in panels +------------------------------------------------------ + +In a whole pile of panel drivers, we have code to make the +prepare/unprepare/enable/disable callbacks behave as no-ops if they've already +been called. To get some idea of the duplicated code, try: + git grep 'if.*>prepared' -- drivers/gpu/drm/panel + git grep 'if.*>enabled' -- drivers/gpu/drm/panel + +In the patch ("drm/panel: Check for already prepared/enabled in drm_panel") +we've moved this check to the core. Now we can most definitely remove the +check from the individual panels and save a pile of code. + +In adition to removing the check from the individual panels, it is believed +that even the core shouldn't need this check and that should be considered +an error if other code ever relies on this check. The check in the core +currently prints a warning whenever something is relying on this check with +dev_warn(). After a little while, we likely want to promote this to a +WARN(1) to help encourage folks not to rely on this behavior. + +Contact: Douglas Anderson <dianders@chromium.org> + +Level: Starter/Intermediate + Core refactorings ================= diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index f634371c717a..4e1c4e42575b 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -105,11 +105,22 @@ EXPORT_SYMBOL(drm_panel_remove); */ int drm_panel_prepare(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; - if (panel->funcs && panel->funcs->prepare) - return panel->funcs->prepare(panel); + if (panel->prepared) { + dev_warn(panel->dev, "Skipping prepare of already prepared panel\n"); + return 0; + } + + if (panel->funcs && panel->funcs->prepare) { + ret = panel->funcs->prepare(panel); + if (ret < 0) + return ret; + } + panel->prepared = true; return 0; } @@ -128,11 +139,22 @@ EXPORT_SYMBOL(drm_panel_prepare); */ int drm_panel_unprepare(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; - if (panel->funcs && panel->funcs->unprepare) - return panel->funcs->unprepare(panel); + if (!panel->prepared) { + dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); + return 0; + } + + if (panel->funcs && panel->funcs->unprepare) { + ret = panel->funcs->unprepare(panel); + if (ret < 0) + return ret; + } + panel->prepared = false; return 0; } @@ -155,11 +177,17 @@ int drm_panel_enable(struct drm_panel *panel) if (!panel) return -EINVAL; + if (panel->enabled) { + dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); + return 0; + } + if (panel->funcs && panel->funcs->enable) { ret = panel->funcs->enable(panel); if (ret < 0) return ret; } + panel->enabled = true; ret = backlight_enable(panel->backlight); if (ret < 0) @@ -187,13 +215,22 @@ int drm_panel_disable(struct drm_panel *panel) if (!panel) return -EINVAL; + if (!panel->enabled) { + dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); + return 0; + } + ret = backlight_disable(panel->backlight); if (ret < 0) DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n", ret); - if (panel->funcs && panel->funcs->disable) - return panel->funcs->disable(panel); + if (panel->funcs && panel->funcs->disable) { + ret = panel->funcs->disable(panel); + if (ret < 0) + return ret; + } + panel->enabled = false; return 0; } diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 432fab2347eb..c6cf75909389 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -198,6 +198,20 @@ struct drm_panel { * the panel is powered up. */ bool prepare_prev_first; + + /** + * @prepared: + * + * If true then the panel has been prepared. + */ + bool prepared; + + /** + * @enabled: + * + * If true then the panel has been enabled. + */ + bool enabled; }; void drm_panel_init(struct drm_panel *panel, struct device *dev, |