Re: [PATCH] net: Select PTP_1588_CLOCK in PTP-specific drivers

From: Clay McClure <clay@daemons.net>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
	Richard Cochran <richardcochran@gmail.com>,
	Nicolas Pitre <nicolas.pitre@linaro.org>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Vladimir Oltean <olteanv@gmail.com>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>,
	Mao Wenan <maowenan@huawei.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Edward Cree <ecree@solarflare.com>,
	Nicolas Pitre <nico@fluxnic.net>,
	Josh Triplett <josh@joshtriplett.org>,
	netdev <netdev@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] net: Select PTP_1588_CLOCK in PTP-specific drivers
Date: Wed, 29 Apr 2020 00:29:59 -0700	[thread overview]
Message-ID: <20200429072959.GA10194@arctic-shiba-lx> (raw)
In-Reply-To: <CAK8P3a2rG-A6_qhU9vrcadZqq2r1FdCDFMVPhSzPEAO83WrA9A@mail.gmail.com>

On Tue, Apr 28, 2020 at 06:07:45PM +0200, Arnd Bergmann wrote:
> On Tue, Apr 28, 2020 at 11:21 AM Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
> > On Tue, Apr 28, 2020 at 11:14 AM Clay McClure <clay@daemons.net> wrote:
> > > Change these drivers back [2] to `select PTP_1588_CLOCK`. Note that this
> > > requires also selecting POSIX_TIMERS, a transitive dependency of
> > > PTP_1588_CLOCK.
> >
> > If these drivers have a hard dependency on PTP_1588_CLOCK, IMHO they
> > should depend on PTP_1588_CLOCK, not select PTP_1588_CLOCK.
> 
> Agreed.

Thanks for reviewing the patch. I'll post v2 using `depends on` shortly.

> Note that for drivers that only optionally use the PTP_1588_CLOCK
> support, we probably want 'depends on PTP_1588_CLOCK ||
> !PTP_1588_CLOCK' (or the syntax replacing it eventually), to avoid the
> case where a built-in driver fails to use a modular ptp implementation.

I see some drivers are starting to do just that, e.g.:

commit 96c34151d157 ("net/mlx5: Kconfig: convert imply usage to weak dependency")

I can post a patch this weekend converting the rest of the drivers.

-- 
Clay