Re: [PATCH v4 6/8] media: imx274: add helper function to fill a reg_8 table chunk

From: Sakari Ailus
Date: Wed Jun 27 2018 - 05:31:04 EST


On Wed, Jun 27, 2018 at 10:13:12AM +0200, Luca Ceresoli wrote:
> Hi Sakari,
>
> On 26/06/2018 14:20, Sakari Ailus wrote:
> > Hi Luca,
> >
> > On Mon, Jun 11, 2018 at 01:35:37PM +0200, Luca Ceresoli wrote:
> >> Tables of struct reg_8 are used to simplify multi-byte register
> >> assignment. However filling these snippets with values computed at
> >> runtime is currently implemented by very similar functions doing the
> >> needed shift & mask manipulation.
> >>
> >> Replace all those functions with a unique helper function to fill
> >> reg_8 tables in a simple and clean way.
> >
> > What's the purpose of writing these registers as multiple I²C writes, when
> > this can be done as a single write (i.e. the address followed by two or
> > three octets of data)?
>
> Good point. The for loops applying the register values (the lines just
> after those changed by my patch) defuse the regmap bulk write capability.
>
> I guess this could be improved not filling any table, but directly
> calling regmap_bulk_write(), passing the u16 or u32 register value with
> proper endianness. No tables, less code. This would replace the present
> patch with a shorter and more effective one. Is it what you was suggesting?

Yes, please.

--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx