[PATCH v2 6/6] drm/vkms: Add a module param to enable/disable the default device

[Jim Shargo]

In many testing circumstances, we will want to just create a new device
and test against that. If we create a default device, it can be annoying
to have to manually select the new device instead of choosing the only
one that exists.

The param, enable_default, is defaulted to true to maintain backwards
compatibility.

Signed-off-by: Jim Shargo <jsha...@chromium.org>
---
 drivers/gpu/drm/vkms/vkms_drv.c | 44 ++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 314a04659c5f..1cb56c090a65 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -42,17 +42,26 @@
 #define DRIVER_MAJOR   1
 #define DRIVER_MINOR   0
 
+static bool enable_default_device = true;
+module_param_named(enable_default_device, enable_default_device, bool, 0444);
+MODULE_PARM_DESC(enable_default_device,
+                "Enable/Disable creating the default device");
+
 static bool enable_cursor = true;
 module_param_named(enable_cursor, enable_cursor, bool, 0444);
-MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
+MODULE_PARM_DESC(enable_cursor,
+                "Enable/Disable cursor support for the default device");
 
 static bool enable_writeback = true;
 module_param_named(enable_writeback, enable_writeback, bool, 0444);
-MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector 
support");
+MODULE_PARM_DESC(
+       enable_writeback,
+       "Enable/Disable writeback connector support for the default device");
 
 static bool enable_overlay;
 module_param_named(enable_overlay, enable_overlay, bool, 0444);
-MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
+MODULE_PARM_DESC(enable_overlay,
+                "Enable/Disable overlay support for the default device");
 
 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
 
@@ -278,10 +287,7 @@ void vkms_remove_device(struct vkms_device *vkms_device)
 static int __init vkms_init(void)
 {
        int ret;
-       struct platform_device *pdev;
-       struct vkms_device_setup vkms_device_setup = {
-               .configfs = NULL,
-       };
+       struct platform_device *default_pdev = NULL;
 
        ret = platform_driver_register(&vkms_platform_driver);
        if (ret) {
@@ -289,19 +295,27 @@ static int __init vkms_init(void)
                return ret;
        }
 
-       pdev = platform_device_register_data(NULL, DRIVER_NAME, 0,
-                                            &vkms_device_setup,
-                                            sizeof(vkms_device_setup));
-       if (IS_ERR(pdev)) {
-               DRM_ERROR("Unable to register default vkms device\n");
-               platform_driver_unregister(&vkms_platform_driver);
-               return PTR_ERR(pdev);
+       if (enable_default_device) {
+               struct vkms_device_setup vkms_device_setup = {
+                       .configfs = NULL,
+               };
+
+               default_pdev = platform_device_register_data(
+                       NULL, DRIVER_NAME, 0, &vkms_device_setup,
+                       sizeof(vkms_device_setup));
+               if (IS_ERR(default_pdev)) {
+                       DRM_ERROR("Unable to register default vkms device\n");
+                       platform_driver_unregister(&vkms_platform_driver);
+                       return PTR_ERR(default_pdev);
+               }
        }
 
        ret = vkms_init_configfs();
        if (ret) {
                DRM_ERROR("Unable to initialize configfs\n");
-               platform_device_unregister(pdev);
+               if (default_pdev)
+                       platform_device_unregister(default_pdev);
+
                platform_driver_unregister(&vkms_platform_driver);
        }
 
-- 
2.41.0.162.gfafddb0af9-goog