Re: [PATCH v2 2/5] arm64: dts: imx8qxp: Add display controller subsystem

[Liu Ying]

On Fri, Oct 16, 2026 at 09:18:06AM -0500, Frank Li wrote:
> On Fri, Oct 16, 2026 at 06:16:38PM +0800, Liu Ying wrote:
>> On Thu, Oct 15, 2026 at 11:22:33AM -0500, Frank Li wrote:
>>> On Thu, Oct 15, 2026 at 11:41:54AM +0800, Liu Ying wrote:
>>>> Hi Alexander,
>>>>
>>>> On Wed, Oct 14, 2026 at 09:16:46AM +0200, Alexander Stein wrote:
>>>>
>>>> [...]
>>>>
>>> ...
>>>>> +
>>>>> +			dc0_framegen1: framegen@5618d400 {
>>>>> +				reg = <0x5618d400 0x98>;
>>>>> +				clocks = <&dc0_disp_lpcg IMX_LPCG_CLK_1>;
>>>>> +				interrupt-parent = <&dc0_intc>;
>>>>> +				interrupts = <28>, <29>, <30>, <31>,
>>>>> +					     <45>, <46>, <47>, <48>;
>>>>> +				interrupt-names = "int0", "int1", "int2", "int3",
>>>>> +						  "primsync_on", "primsync_off",
>>>>> +						  "secsync_on", "secsync_off";
>>>>> +			};
>>>>> +
>>>>> +			dc0_tcon1: tcon@5618e400 {
>>>>> +				reg = <0x5618e400 0x588>;
>>>>> +
>>>>> +				port {
>>>>> +					dc0_disp1_dc0_pixel_combiner_ch1: endpoint {
>>>>> +						remote-endpoint = <&dc0_pixel_combiner_ch1_dc0_disp1>;
>>>>> +					};
>>>>> +				};
>>>>> +			};
>>>>> +		};
>>>>> +	};
>>>>
>>>> I'm thinking that it would be good to have a complete display controller
>>>> DT node in the first place, including those prefetch engines attached to
>>>> fetchunits through the fsl,prg property.
>>>
>>> what's current prefetch engines status?
>>
>> I need to address quite a few comments on v6.
>> Some are difficult.
> 
> If needn't big change when add prefetch engines, should it be fine add this
> part firstly? It'd better than nothings.

Prefetch engine support impacts imx8-dc driver a lot.  I hope we don't need
to support the case where prefetch engines are bypassed.   Adding this part
first means that prefetch engines are bypassed in some device trees.

> 
> Frank
> 
>>
>>> Is it possible merge at v7.5 ?
>>
>> Not sure.
>>
>>>
>>> Frank
>>>
>>>>  In this way, display controller
>>>> driver's life would be easier - all child/grandchild devices are always
>>>> available.  I'm considering to adding a check to the Linux display controller
>>>> driver to ensure the availability(at least for critical child/grandchild
>>>> devices).
>>>>
>>>> --
>>>> Regards,
>>>> Liu Ying
>>>>
>>
>> --
>> Regards,
>> Liu Ying

-- 
Regards,
Liu Ying