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

[Nicolas Dufresne]

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. 

Nicolas

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