[PATCH v2 2/2] drm/komeda: Adds komeda_kms_drop_master

["Lowry Li (Arm Technology China)" <Lowry.Li@arm.com>]

From: "Lowry Li (Arm Technology China)" <Lowry.Li@arm.com>

The komeda internal resources (pipelines) are shared between crtcs,
and resources release by disable_crtc. This commit is working for once
user forgot disabling crtc like app quit abnomally, and then the
resources can not be used by another crtc. Adds drop_master to
shutdown the device and make sure all the komeda resources have been
released and can be used for the next usage.

Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_kms.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 8543860..647bce5 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -54,11 +54,24 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
 	return status;
 }
 
+/* Komeda internal resources (pipelines) are shared between crtcs, and resources
+ * are released by disable_crtc. But if user forget disabling crtc like app quit
+ * abnormally, the resources can not be used by another crtc.
+ * Use drop_master to shutdown the device and make sure all the komeda resources
+ * have been released, and can be used for the next usage.
+ */
+static void komeda_kms_drop_master(struct drm_device *dev,
+				   struct drm_file *file_priv)
+{
+	drm_atomic_helper_shutdown(dev);
+}
+
 static struct drm_driver komeda_kms_driver = {
 	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC |
 			   DRIVER_PRIME | DRIVER_HAVE_IRQ,
 	.lastclose			= drm_fb_helper_lastclose,
 	.irq_handler			= komeda_kms_irq_handler,
+	.master_drop			= komeda_kms_drop_master,
 	.gem_free_object_unlocked	= drm_gem_cma_free_object,
 	.gem_vm_ops			= &drm_gem_cma_vm_ops,
 	.dumb_create			= komeda_gem_cma_dumb_create,
-- 
1.9.1