On Mon, Mar 09, 2020 at 09:19:03PM -0700, Sandeep Patil wrote:

Hi Geert,

On Mon, Mar 09, 2020 at 11:32:06AM +0100, Geert Uytterhoeven wrote:

quoted

Hi Chunyan,

On Mon, Mar 9, 2020 at 9:32 AM Chunyan Zhang [off-list ref] wrote:

quoted

On Mon, 9 Mar 2020 at 16:03, Geert Uytterhoeven [off-list ref] wrote:

quoted

On Thu, Mar 5, 2020 at 11:33 AM Chunyan Zhang [off-list ref] wrote:

quoted

From: Chunyan Zhang <redacted>

The default value of Kconfig for almost all sprd drivers are the same with
ARCH_SPRD, making these drivers built as modules as default would be easier
if we can set ARCH_SPRD as 'm', so this patch change ARCH_SPRD to tristate.

Signed-off-by: Chunyan Zhang <redacted>

Can you actually boot a kernel on a Spreadtrum platform when all platform
and driver support is modular?

Yes, even if all drivers are modular.

Cool. No hard dependencies on e.g. regulators that are turned off when
unused?

quoted

But I hope serial can be builtin, then I can have a console to see
kernel output before loading modules.

No dependency on the clock driver?
Oh, I see you have a hack in the serial driver, to assume default
values when the serial port's parent clock is not found.  That may
limit use of the other serial ports, depending on the actual serial
hardware.
And on Sharkl64, the serial port's clock is a fixed-clock anyway, so
you don't even need the hack.

But in general you cannot rely on that, especially if your SoC has clock
and/or power domains.

BTW, what about the watchdog driver? That one does need a clock, and
loading it too late will reboot your system.

quoted

Also, this's what Google GKI [1] asked :)

Regards,
Chunyan

[1] https://arstechnica.com/gadgets/2019/11/google-outlines-plans-for-mainline-linux-kernel-support-in-android/

Let's see how having everything modular works out on an SoC where all
hardware is part of a clock and power domain.

I'm curious, are there any problems that we should be aware of? We know about
the regulator sync state and consumer-supplier dependencies. [1]

(Adding Saravana inline)

(oops, forgot to paste the link to presentation)
1. https://linuxplumbersconf.org/event/4/contributions/402/attachments/320/544/Solving_issues_associated_with_modules_and_supplier-consumer_dependencies.pdf

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel