Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <1562165800-30721-1-git-send-email-ioana.ciornei@nxp.com> <1562165800-30721-4-git-send-email-ioana.ciornei@nxp.com>
In-Reply-To: <1562165800-30721-4-git-send-email-ioana.ciornei@nxp.com>
From:   Li Yang <leoyang.li@nxp.com>
Date:   Thu, 15 Aug 2019 18:09:21 -0500
Message-ID: <CADRPPNT9LGdMWuBcBnvWXhD8Q-qbTNOzbYp1dRrt0NXb2DBgDw@mail.gmail.com>
Subject: Re: [PATCH 3/3] soc: fsl: FSL_MC_DPIO selects directly FSL_GUTS
To:     Ioana Ciornei <ioana.ciornei@nxp.com>
Cc:     Laurentiu Tudor <laurentiu.tudor@nxp.com>,
        Roy Pledge <Roy.Pledge@nxp.com>,
        lkml <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jul 3, 2019 at 9:58 AM Ioana Ciornei <ioana.ciornei@nxp.com> wrote:
>
> Make FSL_MC_DPIO select directly FSL_GUTS. Without this change we could
> be in a situation where both FSL_MC_DPIO and SOC_BUS are enabled but
> FSL_GUTS is not.
>
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
> ---
>  drivers/soc/fsl/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
> index b6804c04e96f..7e62c1d0aee7 100644
> --- a/drivers/soc/fsl/Kconfig
> +++ b/drivers/soc/fsl/Kconfig
> @@ -22,7 +22,7 @@ config FSL_GUTS
>  config FSL_MC_DPIO
>          tristate "QorIQ DPAA2 DPIO driver"
>          depends on FSL_MC_BUS
> -        select SOC_BUS
> +        select FSL_GUTS

NACK.  Although DPIO only exists on SoCs with the GUTS block for now.
There is no direct dependency between the two IPs.  I don't think we
should add this dependency to make FSL_GUTS not configurable.  Here is
some explaination from kernel documentation:

        select should be used with care. select will force
        a symbol to a value without visiting the dependencies.
        By abusing select you are able to select a symbol FOO even
        if FOO depends on BAR that is not set.
        In general use select only for non-visible symbols
        (no prompts anywhere) and for symbols with no dependencies.
        That will limit the usefulness but on the other hand avoid
        the illegal configurations all over.

We probably shouldn't let it select SOC_BUS either from the beginning,
as the basic feature of DPIO should still work without defining
SOC_BUS.

Regards,
Leo

>          help
>           Driver for the DPAA2 DPIO object.  A DPIO provides queue and
>           buffer management facilities for software to interact with
> --
> 1.9.1
>