Hi Thomas,
On Wed, Jan 25, 2023 at 09:04:09PM +0100, Thomas Zimmermann wrote:
> Initialize the fb-helper structure immediately after its allocation
> in drm_fbdev_generic_setup(). That will make it easier to fill it with
> driver-specific values, such as the preferred BPP.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_fbdev_generic.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
> index 135d58b8007b..63f66325a8a5 100644
> --- a/drivers/gpu/drm/drm_fbdev_generic.c
> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
> @@ -385,8 +385,6 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
> if (dev->fb_helper)
> return drm_fb_helper_hotplug_event(dev->fb_helper);
>
> - drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
> -
> ret = drm_fb_helper_init(dev, fb_helper);
> if (ret)
> goto err;
>From the documentation:
The drm_fb_helper_prepare()
helper must be called first to initialize the minimum required to make
hotplug detection work.
...
To finish up the fbdev helper initialization, the
drm_fb_helper_init() function is called.
So this change do not follow the documentation as drm_fb_helper_init()
is now called before drm_fb_helper_prepare()
I did not follow all the code - but my gut feeling is that the
documentation is right.
Sam
> @@ -456,12 +454,12 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
> fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
> if (!fb_helper)
> return;
> + drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
>
> ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
> if (ret) {
> - kfree(fb_helper);
> drm_err(dev, "Failed to register client: %d\n", ret);
> - return;
> + goto err_drm_client_init;
> }
>
> /*
> @@ -484,5 +482,12 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
> drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
>
> drm_client_register(&fb_helper->client);
> +
> + return;
> +
> +err_drm_client_init:
> + drm_fb_helper_unprepare(fb_helper);
> + kfree(fb_helper);
> + return;
> }
> EXPORT_SYMBOL(drm_fbdev_generic_setup);
> --
> 2.39.0
