[PATCH v2 3/5] pinctrl: renesas: r8a77965: Add R8A774B1 PFC support

[Marek Vasut]

On 10/14/20 1:29 PM, Biju Das wrote:

Hi,

[...]

>>>> Check with the linux maintainers please, surely there should be some
>>>> way to separate the extras in a way that's not too hard to maintain,
>>>> and thus reduce the resulting binary size. For U-Boot, that is quite
>>>> important already, I think the TFA can only load 1 MiB binary in total.
>>>
>>> I agree for bootloader size is important. So I will add macros as per your
>> suggestion (we don't need to look into linux for this).
>>
>> The PFC tables and clock tables are the same between U-Boot and Linux, so if
>> you only change them in U-Boot, it will make it hard to synchronize the tables
>> later with Linux again. Please fix this in Linux and synchronize to U-Boot.
> 
> I have posted a patch for optimizing pin control size for RZ/G2N in Linux [1]
> 
> [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20201014110238.9600-1-biju.das.jz@bp.renesas.com/
> 
> This approach will save ~ 6KB=(3x 2KB/SoC) of memory on RZ/G2[HMN] u-boot with multi dtb support. 
> 
> 1) By compiling out Automotive parts
> $ size drivers/pinctrl/renesas/pfc-r8a77965.o
>    text	   data	    bss	    dec	    hex	filename
>   46141	      0	      0	  46141	   b43d	drivers/pinctrl/renesas/pfc-r8a77965.o
> 
> 2) without patch
> $ size drivers/pinctrl/renesas/pfc-r8a77965.o
>    text	   data	    bss	    dec	    hex	filename
>   48191	      0	      0	  48191	   bc3f	drivers/pinctrl/renesas/pfc-r8a77965.o

Have a look at the size of the image of rcar3_salvator-x_defconfig , it
is just a few kiB short of 1MiB , which is the hard limit. Any size
reduction helps.