[PATCH v4 drm-dp 3/8] drm/hisilicon/hibmc: Add dp serdes cfg in dp process

[Yongbang Shi]

> On Wed, Mar 05, 2025 at 07:26:42PM +0800, Yongbang Shi wrote:
>> From: Baihan Li <libaihan at huawei.com>
>>
>> Add dp serdes cfg in link training process, and related adapting
>> and modificating. Change some init values about training,
>> because we want completely to negotiation process, so we start with
>> the maximum rate and the electrical characteristic level is 0.
> In the commit message there should be a mention, why are you also
> changing hibmc_kms_init().
>
>> Signed-off-by: Baihan Li <libaihan at huawei.com>
>> Signed-off-by: Yongbang Shi <shiyongbang at huawei.com>
>> ---
>> ChangeLog:
>> v3 -> v4:
>>    - add comments for if-statement of dp_init(), suggested by Dmitry Baryshkov.
>> v2 -> v3:
>>    - change commit to an imperative sentence, suggested by Dmitry Baryshkov.
>>    - put HIBMC_DP_HOST_SERDES_CTRL in dp_serdes.h, suggested by Dmitry Baryshkov.
>> v1 -> v2:
>>    - splittting the patch and add more detailed the changes in the commit message, suggested by Dmitry Baryshkov.
>> ---
>>   1                                             |  0
>>   .../gpu/drm/hisilicon/hibmc/dp/dp_config.h    |  1 +
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    |  5 ++-
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c  | 32 ++++++++++++++++---
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  5 +++
>>   .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c   | 12 +++----
>>   6 files changed, 43 insertions(+), 12 deletions(-)
>>   create mode 100644 1
>>
> [...]
>
>> @@ -121,9 +119,11 @@ static int hibmc_kms_init(struct hibmc_drm_private *priv)
>>   		return ret;
>>   	}
>>   
>> -	/* if DP existed, init DP */
>> -	if ((readl(priv->mmio + HIBMC_DP_HOST_SERDES_CTRL) &
>> -	     HIBMC_DP_HOST_SERDES_CTRL_MASK) == HIBMC_DP_HOST_SERDES_CTRL_VAL) {
>> +	/* if the serdes reg is readable and is not equal to 0,
>> +	 * DP existed, and init DP.
>> +	 */
> Nit: A typical format for block comments is:
>
>    /*
>     * Something Something Something
>     */
>
> Please follow it.

Ok, got it.


>> +	ret = readl(priv->mmio + HIBMC_DP_HOST_SERDES_CTRL);
>> +	if (ret) {
>>   		ret = hibmc_dp_init(priv);
>>   		if (ret)
>>   			drm_err(dev, "failed to init dp: %d\n", ret);
>> -- 
>> 2.33.0
>>