Re: [PATCH v1 1/1] drm/mediatek/dp: The register is written with the parsed DTS SSC value.

LIANKUN YANG (杨连坤) <Liankun.Yang@xxxxxxxxxxxx> · Thu, 11 Apr 2024 06:23:10 +0000

On Wed, 2024-04-03 at 16:56 +0200, Krzysztof Kozlowski wrote:
Dear Krzysztof:

The dp_phy device has already been registered through the mtk_dp_register_phy function in the mtk_dp.c file, 
so it cannot be redefined in the dts. Avoid using of_get_child_by_name for this purpose.

 To find the node name, utilize of_find_node_by_name since it has already been registered.

Best regards,
Liankun Yang

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On 03/04/2024 08:41, Krzysztof Kozlowski wrote:
> On 03/04/2024 06:05, Liankun Yang wrote:
>> [Description]
>> Severe screen flickering has been observed on the external display
>> when the DP projection function is used with the market expansion dock.
>>
> 
>> +if (!strcmp(mode_name, RG_XTP_GLB_TXPLL_SSC_DELTA_RBR)) {
>> +regmap_update_bits(dp_phy->regs, ssc_reg_offset,
>> +   XTP_GLB_TXPLL_SSC_DELTA_RBR_DEFAULT, read_value);
>> +} else if (!strcmp(mode_name, RG_XTP_GLB_TXPLL_SSC_DELTA_HBR)) {
>> +read_value = read_value << 16 | 0x0000;
>> +regmap_update_bits(dp_phy->regs, ssc_reg_offset,
>> +   XTP_GLB_TXPLL_SSC_DELTA_HBR_DEFAULT, read_value);
>> +}
>> +
>> +return 0;
>> +}
>> +
>> +static struct device_node *mtk_dp_get_ssc_node(struct phy *phy, struct mtk_dp_phy *dp_phy)
>> +{
>> +struct device_node *mode_node = NULL;
>> +
>> +mode_node = of_find_node_by_name(dp_phy->dev->of_node, SSC_SETTING);
> 
> ?!?!
> You have the node, why do you try to find it?
> 

Wait, that was brainfuck from my side or -ENOCOFFEE. Ignore.

I still have a question though, where did you document new ABI:
dependency on the node name here?

Also, why you are not going through direct children -
of_get_child_by_name()?

Best regards,
Krzysztof

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