Re: [PATCH 08/18] rockchip: pine64: rockpro64: migrate to rockchip_early_misc_init_r

[Dragan Simic <dsimic@manjaro.org>]

Hello Quentin,

On 2024-02-06 13:26, Quentin Schulz wrote:
> On 2/4/24 11:39, Dragan Simic wrote:
>> On 2024-02-04 10:46, Jonas Karlman wrote:
>>> On 2024-02-04 05:21, Dragan Simic wrote:
>>>> On 2024-02-03 16:18, Dragan Simic wrote:
>>>>> On 2024-02-03 15:18, Jonas Karlman wrote:
>>>>>> On 2024-02-03 14:19, Dragan Simic wrote:
>>>>>>> We should add more ifdef guards to rockchip_setup_macaddr(),
>>>>>>> to prevent the execution of its body for devices such as the
>>>>>>> ones listed above, which eliminates the unneeded code from the
>>>>>>> resulting U-Boot images, making them a bit smaller, and saves
>>>>>>> some CPU cycles and a bit of time on boot.  It also prevents
>>>>>>> the unneeded "ethaddr" and "eth1addr" variables from being
>>>>>>> added to the environment.
>>>>>> 
>>>>>> Adding the ethernet addresses only adds a few ms to boot, if you
>>>>>> care
>>>>>> about boot speed, please look into if we can disable
>>>>>> CONFIG_USE_PREBOOT
>>>>>> for these boards, running "usb start" as preboot adds several
>>>>>> seconds
>>>>>> to the boot.
>>>>> 
>>>>> I see, but I personally don't care that much about how long the
>>>>> U-Boot takes to execute;  a couple of seconds more don't bother me
>>>>> much.  I care more about excluding the unneded code.
>>>>> 
>>>>>>> The patch below should do the trick, which also performs a few
>>>>>>> small code cleanups for additional file-level consistency:
>>>>>>> 
>>>>>>> diff --git a/arch/arm/mach-rockchip/misc.c
>>>>>>> b/arch/arm/mach-rockchip/misc.c
>>>>>>> index 7d03f0c2b679..ed5bdab5a648 100644
>>>>>>> --- a/arch/arm/mach-rockchip/misc.c
>>>>>>> +++ b/arch/arm/mach-rockchip/misc.c
>>>>>>> @@ -23,7 +23,8 @@
>>>>>>> 
>>>>>>>   int rockchip_setup_macaddr(void)
>>>>>>>   {
>>>>>>> -#if CONFIG_IS_ENABLED(HASH) && CONFIG_IS_ENABLED(SHA256)
>>>>>>> +#if CONFIG_IS_ENABLED(HASH) && CONFIG_IS_ENABLED(SHA256) && \
>>>>>>> +    CONFIG_IS_ENABLED(GMAC_ROCKCHIP)
>>>>>> 
>>>>>> This would exclude any board not enabling GMAC_ROCKCHIP in U-Boot
>>>>>> but
>>>>>> want a mac-address being set in DT fixup. And for newer RK35xx 
>>>>>> SoCs
>>>>>> the
>>>>>> GMAC_ROCKCHIP driver is not used.
>>>>> 
>>>>> Thanks for pointing that out.  Not good.
>>>>> 
>>>>>> A new Kconfig option should be introduced if there is a need for
>>>>>> some
>>>>>> boards to disable this.
>>>>> 
>>>>> Is there any simpler way to achieve that?  If there isn't, perhaps
>>>>> we could leave rockchip_setup_macaddr() generate the MAC address
>>>>> and rely on fdt_fixup_ethernet() ending up doing nothing when no
>>>>> ethernetX aliases exist.
>>> 
>>> As Chen-Yu Tsai pointed out in one of my prior patches [2]:
>>> 
>>>  The user might be loading a custom FDT for the kernel, or have DT
>>>  overlays stacked on, either could have the "ethernet1" alias while
>>>  the U-boot DT doesn't.
>>> 
>>> So the common rockchip_setup_macaddr() cannot rely on checking for
>>> ethernetX alias, because the fixup may not run against the bundled 
>>> DT.
>>> 
>>> [2]
>>> https://lore.kernel.org/u-boot/CAGb2v66hR5e3nBPZ0C3=h29fS4Um7whfBu7XTAi1sRbzXRAPxg@mail.gmail.com/
>> 
>> I see, we unfortunately cannot know the final outcome in advance, to
>> be able to avoid polluting the environment by adding the "eth1addr"
>> variable if it actually isn't needed, for example.
>> 
>> Though, why can't the user supply an FDT that contains ethernetX
>> aliases 0 through 2, for example, in which case we wouldn't provide
>> a stable MAC address for ethernet2?  Am I missing something, i.e. is
>> there something preventing an ethernet2 alias from being present?
>> 
>>>> After going through the source code once again, I think that adding
>>>> new configuration option would be warranted, because it would 
>>>> exclude
>>>> two sizable chunks of code from the resulting U-Boot images, and
>>>> because it would avoid polluting the environment with a couple of
>>>> unneeded variables.
>>> 
>>> Yes a new Kconfig option would be preferred.
>>> 
>>>> I'll go ahead and implement this, and I hope that the patch will be
>>>> received well.
>>> 
>>> Great :-)
>> 
>> Thanks. :)  Got it implemented already and tested a bit.  I need to
>> write the patch and series summaries, and I'll send them over.
>> 
>> Regarding the above-described uncertainty about what ethernetX aliases
>> the final FDT containts, I'd say that ignoring the ethernetX aliases
>> completely for the Pinebook Pro and the Pinephone Pro is safe and 
>> valid,
>> because those are actual devices, instead of being development boards
>> for which the final hardware configuration is determined by the user.
>> I can hardly see anyone adding an Ethernet interface to them, except
>> by plugging in a USB Ethernet dongle.
>> 
>> I hope you agree.
> 
> What should be done with the patches for Pinephone/Pinebook Pro then?
> Since I was asked to wait on your answer/patches before respinning the
> patch series, I would like to know what to do with them :) Drop the
> patches for now or keep them as is?

Your patches are fine, just please update their subjects as I already
suggested.  The patches I'll send a bit later will resolve the issues
I raised previously for your patches, together with doing a bit more,
so there's no need to change your patches further.