[GIT PULL] Broadcom soc changes for v4.4

Arnd Bergmann arnd at arndb.de
Fri Oct 9 11:23:52 PDT 2015


On Friday 09 October 2015 10:01:39 Florian Fainelli wrote:
> On 09/10/15 08:46, Arnd Bergmann wrote:
> > On Friday 02 October 2015 15:20:58 Florian Fainelli wrote:
> >> This pull request contains the following Broadcom SoC platform and driver changes:
> >>
> >> - Brian Norris create a drivers/soc/brcmstb/ stub and then adds support for S2/S3/S5
> >>   suspend/resume modes for the Broadcom BCM7xxx Set Top Box SoCs
> > 
> > I'm not overly happy with this part of the code (sorry Brian):
> > 
> > - it looks like it should be a cpuidle driver. Not completely sure about this,
> >   but I'd like to see at least an Ack from the cpuidle maintainers to confirm
> >   that they want it to be done in drivers/soc
> 
> Could you clarify how you think this should be fitting in the cpuidle
> framework? This is system-wide S2/S3/S5 states we are talking about
> here, and that comes with specific constraints, like moving code from
> DRAM execution to SRAM execution for instance, not sure where cpuidle
> can help with that. And if it does, how we coordinate with that framework.

Ok, I see. So probably not cpuidle then, but I'd still have a better
feeling if this was reviewed by someone who understands power management
and is outside of the brcmstb team.

Maybe just send it to linux-pm to get feedback from the suspend maintainers?

> > - any code here that is not going into a cpuidle driver for this part looks
> >   like it's better suited to go to arch/arm/mach-bcm, as the code doesn't
> >   feel like a driver. This is of course a gray area, and can be debated.
> 
> There are some large portions of this code that are shared between SoCs,
> past, current and future chips, with the exception of the small assembly
> part which needs to be architecture specific for obvious reasons.
> 
> For instance, the power state machine code is fairly SoC-independant,
> and to some extent, the DDR controller code is as well, that is what
> motivated putting that code here, so it can be re-used in the future
> when we submit support for new chips as well.

Maybe drivers/firmware/broadcom/ then? That directory already
exists and the main parts seem to be for a firmware interface.

The DDR controller stuff probably better fits into drivers/memory/,
which already has similar bits from other platforms. Of course
that implies restructuring the code a bit to separate the two.

	Arnd



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