Re: [PATCH 2/5] nvmem: mtk-efuse: use stack for nvmem_config instead of malloc'ing it

From: Sean Wang
Date: Fri Sep 22 2017 - 00:00:13 EST


Hi, Masahiro

On Thu, 2017-09-21 at 11:09 +0900, Masahiro Yamada wrote:
> Hi Sean,
>
>
> 2017-09-21 1:32 GMT+09:00 Sean Wang <sean.wang@xxxxxxxxxxxx>:
> > Hi, Masahiro
> >
> > For maintainability, I felt it's better if we use the same way to
> > register nvmem as that most drivers does under nvmem usually using
> > static structure. Otherwise, they should also be changed to use the
> > one-time data in stack to avoid extra bytes to keep them.
> >
> > Sean
>
>
> Srinivas and I discussed the best practice for allocating nvmem_config.
> https://lkml.org/lkml/2017/9/11/4
>
> From the discussion, static structure is possible only when
> the system has one instance of the device.
>

thank you for your detailed explanation

> If you know this is the case for mediatek,
> yes, you can turn it into static,
> but it is not always possible.
> For example, Socionext SoCs have
> two banks of efuse devices.
>

there should be only one instance of nvmem for mediatek soc, currently


> So, if we want to align the coding style for consistency,
> nvmem in stack is safe and efficient, I think.
>
>
> Moving one-time data into stack slightly
> reduces the kernel image size.
>
>

agreed on those statements, indeed bigger struct uart_8250_port is still
used on stack for configuring in a lot 8250 driver, so

Acked-by: Sean Wang <sean.wang@xxxxxxxxxxxx>