[PATCH v5 6/7] drm/vkms: Add a module param to enable/disable the default device

Brandon Pollack
2023-08-28T08:21:01Z

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 <jshargo@chromium.org>
Signed-off-by: Brandon Pollack <brpol@chromium.org>
---
drivers/gpu/drm/vkms/vkms_drv.c | 45 ++++++++++++++++++++++-----------
1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 6e7f20681890..293bebf8e8ce 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);

@@ -99,6 +108,7 @@ static int vkms_config_show(struct seq_file *m, void *data)
struct drm_device *dev = entry->dev;
struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);

+ seq_printf(m, "default_device=%d\n", enable_default_device);
seq_printf(m, "writeback=%d\n", vkmsdev->config.writeback);
seq_printf(m, "cursor=%d\n", vkmsdev->config.cursor);
seq_printf(m, "overlay=%d\n", vkmsdev->config.overlay);
@@ -297,10 +307,7 @@ 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) {
@@ -308,19 +315,27 @@ 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);
}

--
2.42.0.rc1.204.g551eb34607-goog