Re: [PATCH v9 27/28] media: iris: enable video driver probe of SM8250 SoC

[Dikshita Agarwal]

On 1/7/2025 7:27 PM, Nicolas Dufresne wrote:
> Le lundi 23 décembre 2024 à 16:21 +0530, Dikshita Agarwal a écrit :
>>
>> On 12/23/2024 4:00 PM, Mauro Carvalho Chehab wrote:
>>> Em Thu, 12 Dec 2024 17:21:49 +0530
>>> Dikshita Agarwal <quic_dikshita@xxxxxxxxxxx> escreveu:
>>>
>>>> +	.dma_mask = GENMASK(31, 29) - 1,
>>>
>>> Setting a mask to GENMASK() - 1 sounds weird. Is it really what you want?
>>> I so, why?
>>>
>> Hi Mauro,
>>
>> the value of this dma mask should be 0xe0000000 -1.
>>
>> The background for the same is, 0xe0000000 onward memory space is allocated
>> for IO register space so we are restricting the driver buffer allocations
>> to 0xe0000000 - 1.
>>
>> Based on the comments received in the past, we are using GENMASK to
>> generate 0xe0000000.
>>
>> Does this answer your query or I missed something?
> 
> I'm not sure it will do what you want. (0xe0000000 -1) matches ~BIT(29). Perhaps
> you wanted to use ~0xe0000000. 
> 
value of dma mask is coming as expected with GENMASK(31, 29) - 1

qcom-iris aa00000.video-codec: dma_mask DFFFFFFF (0xe0000000 -1)

Thanks,
Dikshita
> Nicolas
> 
>>
>> Thanks,
>> Dikshita
>>> Thanks,
>>> Mauro
>