Re: [PATCH v5 19/25] drm: kirin: Add register connect helper functions in drm init

Daniel Vetter
2020-04-07T08:02:45Z

On Wed, Aug 21, 2019 at 1:06 AM John Stultz <john.stultz@linaro.org> wrote:
>
> From: Xu YiPing <xuyiping@hisilicon.com>
>
> As part of refactoring the kirin driver to better support
> different hardware revisions, this patch adds a flag to the
> device specific driver data so that we can conditionally
> register the connectors at init.
>
> Cc: Rongrong Zou <zourongrong@gmail.com>
> Cc: Xinliang Liu <z.liuxinliang@hisilicon.com>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: dri-devel <dri-devel@lists.freedesktop.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Acked-by: Xinliang Liu <z.liuxinliang@hisilicon.com>
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Xu YiPing <xuyiping@hisilicon.com>
> [jstultz: reworded commit message]
> Signed-off-by: John Stultz <john.stultz@linaro.org>

Whatever it is you're doing, this is nonsense. drm_dev_register does
register connectors for you. If you hotplug connectors later on, you
have to register them (manually), but definitely that should happen in
the hotplug code. General rule: If it's not a hotplugged dp mst
connector, calling drm_connector_register from drivers is pointless
(and yes I know there's tons of that stuff around, for historical
reasons).

Further the flag isn't even set, so this is just dead code.

Please revert.

Thanks, Daniel

> ---
> v5: checkpatch --strict whitespace fixups noticed by Sam
> ---
> .../gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 1 +
> .../gpu/drm/hisilicon/kirin/kirin_drm_drv.c | 43 +++++++++++++++++++
> .../gpu/drm/hisilicon/kirin/kirin_drm_drv.h | 1 +
> 3 files changed, 45 insertions(+)
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 21c5d457a97d..89bdc0388138 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -1073,6 +1073,7 @@ static struct drm_driver ade_driver = {
> };
>
> struct kirin_drm_data ade_driver_data = {
> + .register_connects = false,
> .num_planes = ADE_CH_NUM,
> .prim_plane = ADE_CH1,
> .channel_formats = channel_formats,
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
> index c9faaa848cc6..68de8838da3c 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c
> @@ -98,6 +98,40 @@ static int compare_of(struct device *dev, void *data)
> return dev->of_node == data;
> }
>
> +static int kirin_drm_connectors_register(struct drm_device *dev)
> +{
> + struct drm_connector *connector;
> + struct drm_connector *failed_connector;
> + struct drm_connector_list_iter conn_iter;
> + int ret;
> +
> + mutex_lock(&dev->mode_config.mutex);
> + drm_connector_list_iter_begin(dev, &conn_iter);
> + drm_for_each_connector_iter(connector, &conn_iter) {
> + ret = drm_connector_register(connector);
> + if (ret) {
> + failed_connector = connector;
> + goto err;
> + }
> + }
> + drm_connector_list_iter_end(&conn_iter);
> + mutex_unlock(&dev->mode_config.mutex);
> +
> + return 0;
> +
> +err:
> + drm_connector_list_iter_begin(dev, &conn_iter);
> + drm_for_each_connector_iter(connector, &conn_iter) {
> + if (failed_connector == connector)
> + break;
> + drm_connector_unregister(connector);
> + }
> + drm_connector_list_iter_end(&conn_iter);
> + mutex_unlock(&dev->mode_config.mutex);
> +
> + return ret;
> +}
> +
> static int kirin_drm_bind(struct device *dev)
> {
> struct drm_device *drm_dev;
> @@ -117,8 +151,17 @@ static int kirin_drm_bind(struct device *dev)
>
> drm_fbdev_generic_setup(drm_dev, 32);
>
> + /* connectors should be registered after drm device register */
> + if (driver_data->register_connects) {
> + ret = kirin_drm_connectors_register(drm_dev);
> + if (ret)
> + goto err_drm_dev_unregister;
> + }
> +
> return 0;
>
> +err_drm_dev_unregister:
> + drm_dev_unregister(drm_dev);
> err_kms_cleanup:
> kirin_drm_kms_cleanup(drm_dev);
> err_drm_dev_put:
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h
> index fdbfc4a90f22..95f56c9960d5 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h
> @@ -39,6 +39,7 @@ struct kirin_drm_data {
> u32 channel_formats_cnt;
> int config_max_width;
> int config_max_height;
> + bool register_connects;
> u32 num_planes;
> u32 prim_plane;
>
> --
> 2.17.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch