From dcbd5dcc956e2331414fd7020b4655df08deeb87 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Tue, 1 Apr 2025 08:11:39 +0300 Subject: [PATCH 3336/5403] drm/panel: make prepare/enable and disable/unprepare calls return void Now there are no users of the return value of the drm_panel_prepare(), drm_panel_unprepare(), drm_panel_enable() and drm_panel_disable() calls. Usually these calls are performed from the atomic callbacks, where it is impossible to return an error. Stop returning error codes and return void instead. Reviewed-by: Neil Armstrong Link: https://lore.kernel.org/r/20250401-panel-return-void-v1-7-93e1be33dc8d@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/drm_panel.c | 54 ++++++++++++++----------------------- include/drm/drm_panel.h | 8 +++--- 2 files changed, 24 insertions(+), 38 deletions(-) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 99b348782ce3..650de4da0853 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -106,21 +106,21 @@ EXPORT_SYMBOL(drm_panel_remove); * * Calling this function will enable power and deassert any reset signals to * the panel. After this has completed it is possible to communicate with any - * integrated circuitry via a command bus. - * - * Return: 0 on success or a negative error code on failure. + * integrated circuitry via a command bus. This function cannot fail (as it is + * called from the pre_enable call chain). There will always be a call to + * drm_panel_disable() afterwards. */ -int drm_panel_prepare(struct drm_panel *panel) +void drm_panel_prepare(struct drm_panel *panel) { struct drm_panel_follower *follower; int ret; if (!panel) - return -EINVAL; + return; if (panel->prepared) { dev_warn(panel->dev, "Skipping prepare of already prepared panel\n"); - return 0; + return; } mutex_lock(&panel->follower_lock); @@ -139,11 +139,8 @@ int drm_panel_prepare(struct drm_panel *panel) follower->funcs->panel_prepared, ret); } - ret = 0; exit: mutex_unlock(&panel->follower_lock); - - return ret; } EXPORT_SYMBOL(drm_panel_prepare); @@ -155,16 +152,14 @@ EXPORT_SYMBOL(drm_panel_prepare); * reset, turn off power supplies, ...). After this function has completed, it * is usually no longer possible to communicate with the panel until another * call to drm_panel_prepare(). - * - * Return: 0 on success or a negative error code on failure. */ -int drm_panel_unprepare(struct drm_panel *panel) +void drm_panel_unprepare(struct drm_panel *panel) { struct drm_panel_follower *follower; int ret; if (!panel) - return -EINVAL; + return; /* * If you are seeing the warning below it likely means one of two things: @@ -177,7 +172,7 @@ int drm_panel_unprepare(struct drm_panel *panel) */ if (!panel->prepared) { dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); - return 0; + return; } mutex_lock(&panel->follower_lock); @@ -196,11 +191,8 @@ int drm_panel_unprepare(struct drm_panel *panel) } panel->prepared = false; - ret = 0; exit: mutex_unlock(&panel->follower_lock); - - return ret; } EXPORT_SYMBOL(drm_panel_unprepare); @@ -210,26 +202,26 @@ EXPORT_SYMBOL(drm_panel_unprepare); * * Calling this function will cause the panel display drivers to be turned on * and the backlight to be enabled. Content will be visible on screen after - * this call completes. - * - * Return: 0 on success or a negative error code on failure. + * this call completes. This function cannot fail (as it is called from the + * enable call chain). There will always be a call to drm_panel_disable() + * afterwards. */ -int drm_panel_enable(struct drm_panel *panel) +void drm_panel_enable(struct drm_panel *panel) { int ret; if (!panel) - return -EINVAL; + return; if (panel->enabled) { dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); - return 0; + return; } if (panel->funcs && panel->funcs->enable) { ret = panel->funcs->enable(panel); if (ret < 0) - return ret; + return; } panel->enabled = true; @@ -237,8 +229,6 @@ int drm_panel_enable(struct drm_panel *panel) if (ret < 0) DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n", ret); - - return 0; } EXPORT_SYMBOL(drm_panel_enable); @@ -249,15 +239,13 @@ EXPORT_SYMBOL(drm_panel_enable); * This will typically turn off the panel's backlight or disable the display * drivers. For smart panels it should still be possible to communicate with * the integrated circuitry via any command bus after this call. - * - * Return: 0 on success or a negative error code on failure. */ -int drm_panel_disable(struct drm_panel *panel) +void drm_panel_disable(struct drm_panel *panel) { int ret; if (!panel) - return -EINVAL; + return; /* * If you are seeing the warning below it likely means one of two things: @@ -270,7 +258,7 @@ int drm_panel_disable(struct drm_panel *panel) */ if (!panel->enabled) { dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); - return 0; + return; } ret = backlight_disable(panel->backlight); @@ -281,11 +269,9 @@ int drm_panel_disable(struct drm_panel *panel) if (panel->funcs && panel->funcs->disable) { ret = panel->funcs->disable(panel); if (ret < 0) - return ret; + return; } panel->enabled = false; - - return 0; } EXPORT_SYMBOL(drm_panel_disable); diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 31d84f901c51..843fb756a295 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -316,11 +316,11 @@ void drm_panel_put(struct drm_panel *panel); void drm_panel_add(struct drm_panel *panel); void drm_panel_remove(struct drm_panel *panel); -int drm_panel_prepare(struct drm_panel *panel); -int drm_panel_unprepare(struct drm_panel *panel); +void drm_panel_prepare(struct drm_panel *panel); +void drm_panel_unprepare(struct drm_panel *panel); -int drm_panel_enable(struct drm_panel *panel); -int drm_panel_disable(struct drm_panel *panel); +void drm_panel_enable(struct drm_panel *panel); +void drm_panel_disable(struct drm_panel *panel); int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector); -- 2.54.0