[Intel-gfx] [PATCH 15/44] drm/i915: Make panel/backlight safe to setup/cleanup multiple times

[Chris Wilson]

Allow everyone to call intel_panel_setup_backlight() (i.e. only take
effect if we have previously been initialised for use as a panel) and,
for paranoia, allow intel_panel_cleanup_backlight() to be called
multiple times.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h   | 1 +
 drivers/gpu/drm/i915/intel_panel.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 8dc67adace6b..111038e29ec3 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -201,6 +201,7 @@ struct intel_panel {
 	struct drm_display_mode *fixed_mode;
 	struct drm_display_mode *downclock_mode;
 	int fitting_mode;
+	bool is_panel;
 
 	/* backlight */
 	struct {
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index f0b1602c3258..8bd076b11af1 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -1670,6 +1670,9 @@ int intel_panel_setup_backlight(struct drm_connector *connector, enum pipe pipe)
 	struct intel_panel *panel = &intel_connector->panel;
 	int ret;
 
+	if (!panel->is_panel)
+		return 0;
+
 	if (!dev_priv->vbt.backlight.present) {
 		if (dev_priv->quirks & QUIRK_BACKLIGHT_PRESENT) {
 			DRM_DEBUG_KMS("no backlight present per VBT, but present per quirk\n");
@@ -1709,6 +1712,9 @@ void intel_panel_destroy_backlight(struct drm_connector *connector)
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct intel_panel *panel = &intel_connector->panel;
 
+	if (!panel->backlight.present)
+		return;
+
 	/* dispose of the pwm */
 	if (panel->backlight.pwm)
 		pwm_put(panel->backlight.pwm);
@@ -1796,6 +1802,7 @@ int intel_panel_init(struct intel_panel *panel,
 
 	panel->fixed_mode = fixed_mode;
 	panel->downclock_mode = downclock_mode;
+	panel->is_panel = true;
 
 	return 0;
 }
-- 
2.8.1