Re: [PATCH -next 1/2] ACPI: Enable ACPI_PROCESSOR for RISC-V

From: Sunil V L <sunilvl@ventanamicro.com>
To: Andrew Jones <ajones@ventanamicro.com>
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>, Anup Patel <anup@brainfault.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Conor Dooley <conor@kernel.org>,
	Atish Kumar Patra <atishp@rivosinc.com>
Subject: Re: [PATCH -next 1/2] ACPI: Enable ACPI_PROCESSOR for RISC-V
Date: Thu, 11 Jan 2024 16:59:47 +0530	[thread overview]
Message-ID: <ZZ/RK49zoFtSt4Ed@sunil-laptop> (raw)
In-Reply-To: <20240111-bb411d2dd39eb859dd049fa0@orel>

On Thu, Jan 11, 2024 at 11:00:12AM +0100, Andrew Jones wrote:
> On Thu, Jan 11, 2024 at 03:00:57PM +0530, Sunil V L wrote:
> > The ACPI processor driver is not currently enabled for RISC-V.
> > This is required to enable CPU related functionalities like
> > LPI and CPPC. Hence, enable ACPI_PROCESSOR for RISC-V.
> > 
> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > ---
> >  drivers/acpi/Kconfig | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > index f819e760ff19..9a920752171c 100644
> > --- a/drivers/acpi/Kconfig
> > +++ b/drivers/acpi/Kconfig
> > @@ -282,7 +282,7 @@ config ACPI_CPPC_LIB
> >  
> >  config ACPI_PROCESSOR
> >  	tristate "Processor"
> > -	depends on X86 || ARM64 || LOONGARCH
> > +	depends on X86 || ARM64 || LOONGARCH || RISCV
> >  	select ACPI_PROCESSOR_IDLE
> >  	select ACPI_CPU_FREQ_PSS if X86 || LOONGARCH
> >  	select THERMAL
> > -- 
> > 2.34.1
> >
> 
> Hi Sunil,
> 
> Typically we'll want the Kconfig changes to come at the end of a series,
> or squashed into the patch that adds support for it, otherwise there's
> risk of build breakage during bisection. In this case, we're safe because
> the two new functions (I looked ahead) have __weak versions when they're
> not present.
> 
Sure. Let me swap the order of the patches.

> Also, interestingly, it looks like this ancient line
> 
>  obj-$(CONFIG_ACPI_PROCESSOR)    += processor.o
> 
> in drivers/acpi/Makefile should be removed, since there's no
> drivers/acpi/processor.c file. I guess the make process silently
> filters object files which don't have corresponding source files?
> Maybe we should write a Makefile analyzer to see what other lines
> can be removed...
>
Interesting. 

Hi Rafael, any thoughts?

> Anyway, for this patch, which I'd prefer to be swapped in order with
> the other patch, or just squashed into the other patch,
>
I prefer to keep as 2 separate patches. I will swap the order.

> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> 
Thanks!
Sunil 