Re: [PATCH v7 drm-dp 5/9] drm/hisilicon/hibmc: Getting connector info and EDID by using AUX channel

[Yongbang Shi <shiyongbang@huawei.com>]

> On Mon, 24 Mar 2025, Yongbang Shi <shiyongbang@huawei.com> wrote:
>>> On Wed, 19 Mar 2025, Yongbang Shi <shiyongbang@huawei.com> wrote:
>>>> From: Baihan Li <libaihan@huawei.com>
>>>>
>>>> Add registering drm_aux and use it to get connector edid with drm
>>>> functions. Add ddc channel in connector initialization to put drm_aux
>>>> in drm_connector.
>>>>
>>>> Signed-off-by: Baihan Li <libaihan@huawei.com>
>>>> Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
>>>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>>> ---
>>>> ChangeLog:
>>>> v6 -> v7:
>>>>     - add if statement about drm aux in hibmc_dp_connector_get_modes(), suggested by Jani Nikula
>>> I don't understand this, and I did not suggest such a thing.
>>>
>>> BR,
>>> Jani.
>>>
>> Hi Jani,
>>
>> Is the modification of v8 correct?
> I never received that for whatever reason.

Here's the link: https://lore.kernel.org/all/20250320101455.2538835-1-shiyongbang@huawei.com/


>>
>>>> v5 -> v6:
>>>>     - move the detect_ctx() to the patch 7/9.
>>>> v2 -> v3:
>>>>     - Capitalized EDID and AUX, suggested by Dmitry Baryshkov.
>>>> v1 -> v2:
>>>>     - deleting type conversion, suggested by Dmitry Baryshkov.
>>>>     - deleting hibmc_dp_connector_get_modes() and using drm_connector_helper_get_modes(), suggested by Dmitry Baryshkov.
>>>> ---
>>>>    drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c   |  3 +-
>>>>    .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 35 ++++++++++++++++---
>>>>    .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h   |  5 +++
>>>>    3 files changed, 37 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
>>>> index ded9e7ce887a..e0bb9b14d9d8 100644
>>>> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
>>>> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
>>>> @@ -161,7 +161,8 @@ void hibmc_dp_aux_init(struct hibmc_dp *dp)
>>>>    				 HIBMC_DP_MIN_PULSE_NUM);
>>>>    
>>>>    	dp->aux.transfer = hibmc_dp_aux_xfer;
>>>> -	dp->aux.is_remote = 0;
>>>> +	dp->aux.name = kasprintf(GFP_KERNEL, "HIBMC DRM dp aux");
>>>> +	dp->aux.drm_dev = dp->drm_dev;
>>>>    	drm_dp_aux_init(&dp->aux);
>>>>    	dp->dp_dev->aux = &dp->aux;
>>>>    }
>>>> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
>>>> index 603d6b198a54..0256724d8b9b 100644
>>>> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
>>>> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
>>>> @@ -15,11 +15,20 @@
>>>>    
>>>>    static int hibmc_dp_connector_get_modes(struct drm_connector *connector)
>>>>    {
>>>> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
>>>> +	const struct drm_edid *drm_edid;
>>>>    	int count;
>>>>    
>>>> -	count = drm_add_modes_noedid(connector, connector->dev->mode_config.max_width,
>>>> -				     connector->dev->mode_config.max_height);
>>>> -	drm_set_preferred_mode(connector, 1024, 768); // temporary implementation
>>>> +	if (!dp->aux.name)
>>>> +		return 0;
>>>> +
>>>> +	drm_edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
>>>> +
>>>> +	drm_edid_connector_update(connector, drm_edid);
>>>> +
>>>> +	count = drm_edid_connector_add_modes(connector);
>>>> +
>>>> +	drm_edid_free(drm_edid);
>>>>    
>>>>    	return count;
>>>>    }
>>>> @@ -28,12 +37,28 @@ static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
>>>>    	.get_modes = hibmc_dp_connector_get_modes,
>>>>    };
>>>>    
>>>> +static int hibmc_dp_late_register(struct drm_connector *connector)
>>>> +{
>>>> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
>>>> +
>>>> +	return drm_dp_aux_register(&dp->aux);
>>>> +}
>>>> +
>>>> +static void hibmc_dp_early_unregister(struct drm_connector *connector)
>>>> +{
>>>> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
>>>> +
>>>> +	drm_dp_aux_unregister(&dp->aux);
>>>> +}
>>>> +
>>>>    static const struct drm_connector_funcs hibmc_dp_conn_funcs = {
>>>>    	.reset = drm_atomic_helper_connector_reset,
>>>>    	.fill_modes = drm_helper_probe_single_connector_modes,
>>>>    	.destroy = drm_connector_cleanup,
>>>>    	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>>>>    	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>>>> +	.late_register = hibmc_dp_late_register,
>>>> +	.early_unregister = hibmc_dp_early_unregister,
>>>>    };
>>>>    
>>>>    static inline int hibmc_dp_prepare(struct hibmc_dp *dp, struct drm_display_mode *mode)
>>>> @@ -103,8 +128,8 @@ int hibmc_dp_init(struct hibmc_drm_private *priv)
>>>>    
>>>>    	drm_encoder_helper_add(encoder, &hibmc_dp_encoder_helper_funcs);
>>>>    
>>>> -	ret = drm_connector_init(dev, connector, &hibmc_dp_conn_funcs,
>>>> -				 DRM_MODE_CONNECTOR_DisplayPort);
>>>> +	ret = drm_connector_init_with_ddc(dev, connector, &hibmc_dp_conn_funcs,
>>>> +					  DRM_MODE_CONNECTOR_DisplayPort, &dp->aux.ddc);
>>>>    	if (ret) {
>>>>    		drm_err(dev, "init dp connector failed: %d\n", ret);
>>>>    		return ret;
>>>> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
>>>> index d982f1e4b958..3ddd71aada66 100644
>>>> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
>>>> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
>>>> @@ -47,6 +47,11 @@ static inline struct hibmc_vdac *to_hibmc_vdac(struct drm_connector *connector)
>>>>    	return container_of(connector, struct hibmc_vdac, connector);
>>>>    }
>>>>    
>>>> +static inline struct hibmc_dp *to_hibmc_dp(struct drm_connector *connector)
>>>> +{
>>>> +	return container_of(connector, struct hibmc_dp, connector);
>>>> +}
>>>> +
>>>>    static inline struct hibmc_drm_private *to_hibmc_drm_private(struct drm_device *dev)
>>>>    {
>>>>    	return container_of(dev, struct hibmc_drm_private, dev);