[PATCH drm-dp 10/10] drm/hisilicon/hibmc: fix no showing problem with loading hibmc manually

[Yongbang Shi]

> On Fri, May 30, 2025 at 05:54:32PM +0800, Yongbang Shi wrote:
>> From: Baihan Li <libaihan at huawei.com>
>>
>> When using command rmmod and insmod, there is no showing in second time
>> insmoding. Because DP controller won't send HPD signals, if connection
>> doesn't change or controller isn't reset. So add reset before unreset
>> in hibmc_dp_hw_init().
>>
>> Fixes: 94ee73ee3020 ("drm/hisilicon/hibmc: add dp hw moduel in hibmc driver")
> Technically... yes and no. The function was written this way in that
> commit, however HPD signals were not handled until the latter commit.

Alright, can I put 2 commits here?


>> Signed-off-by: Baihan Li <libaihan at huawei.com>
>> ---
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
>> index 4f93d60b932b..e1b9589ce639 100644
>> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
>> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
>> @@ -172,13 +172,15 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
>>   	dp_dev->link.cap.lanes = 0x2;
>>   	dp_dev->link.cap.link_rate = DP_LINK_BW_8_1;
>>   
>> -	/* hdcp data */
>> -	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
>>   	/* int init */
>>   	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
>>   	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
>>   	/* rst */
>> +	writel(0, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
>> +	usleep_range(30, 50);
>>   	writel(HIBMC_DP_DPTX_RST, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
>> +	/* hdcp data */
>> +	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
> There are two independent changes here. Split them into two commits.

Okay!


>>   	/* clock enable */
>>   	writel(HIBMC_DP_CLK_EN, dp_dev->base + HIBMC_DP_DPTX_CLK_CTRL);
>>   
>> -- 
>> 2.33.0
>>