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From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
To: Doug Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Cc: Max Schwarz <max.schwarz-BGeptl67XyCzQB+pC5nmwQ@public.gmane.org>,
	Chris Zhong <zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>,
	"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
	<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
	"linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] i2c-rk3x: move setup to the earlier subsys initcall
Date: Mon, 22 Sep 2014 19:13:27 +0200	[thread overview]
Message-ID: <20140922171325.GB1404@katana> (raw)
In-Reply-To: <CAD=FV=VUoK8SDng6O4-VVq8UZf88b3bSe-hQMht3R2nmYXqMFQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

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Hi,

> In general you are correct.  You can get by with lots of probe
> deferrals.  I don't personally know of any case where things are
> broken with the current code, but it's really nice to avoid the
> deferrals if possible.

Yes, we all want proper dependencies and ordering, yet deferred probing
is the best we have.

> Given that this is a core SoC i2c bus and is used for _a lot_ of
> external connectivity (including for connecting to the primary
> regulator on most boards), bumping up the priority in the init order
> makes a lot of sense to me.
> 
> This also matches the i2c busses of most other major SoCs.  A selected
> few examples:
> 
> i2c-gpio.c:subsys_initcall(i2c_gpio_init);
> i2c-omap.c:subsys_initcall(omap_i2c_init_driver);
> i2c-s3c2410.c:subsys_initcall(i2c_adap_s3c_init);
> i2c-tegra.c:subsys_initcall(tegra_i2c_init_driver);

They were "lucky" to be around before deferred probing and using
subsys_initcall was always considered a hack. I am not accepting new
users of this hack unless there is really no other solution.

So, NACK, since it doesn't solve a problem.

Regards,

   Wolfram


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WARNING: multiple messages have this Message-ID (diff)
From: wsa@the-dreams.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c-rk3x: move setup to the earlier subsys initcall
Date: Mon, 22 Sep 2014 19:13:27 +0200	[thread overview]
Message-ID: <20140922171325.GB1404@katana> (raw)
In-Reply-To: <CAD=FV=VUoK8SDng6O4-VVq8UZf88b3bSe-hQMht3R2nmYXqMFQ@mail.gmail.com>

Hi,

> In general you are correct.  You can get by with lots of probe
> deferrals.  I don't personally know of any case where things are
> broken with the current code, but it's really nice to avoid the
> deferrals if possible.

Yes, we all want proper dependencies and ordering, yet deferred probing
is the best we have.

> Given that this is a core SoC i2c bus and is used for _a lot_ of
> external connectivity (including for connecting to the primary
> regulator on most boards), bumping up the priority in the init order
> makes a lot of sense to me.
> 
> This also matches the i2c busses of most other major SoCs.  A selected
> few examples:
> 
> i2c-gpio.c:subsys_initcall(i2c_gpio_init);
> i2c-omap.c:subsys_initcall(omap_i2c_init_driver);
> i2c-s3c2410.c:subsys_initcall(i2c_adap_s3c_init);
> i2c-tegra.c:subsys_initcall(tegra_i2c_init_driver);

They were "lucky" to be around before deferred probing and using
subsys_initcall was always considered a hack. I am not accepting new
users of this hack unless there is really no other solution.

So, NACK, since it doesn't solve a problem.

Regards,

   Wolfram

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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Doug Anderson <dianders@chromium.org>
Cc: Max Schwarz <max.schwarz@online.de>,
	Chris Zhong <zyw@rock-chips.com>,
	linux-rockchip@lists.infradead.org,
	Heiko Stuebner <heiko@sntech.de>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] i2c-rk3x: move setup to the earlier subsys initcall
Date: Mon, 22 Sep 2014 19:13:27 +0200	[thread overview]
Message-ID: <20140922171325.GB1404@katana> (raw)
In-Reply-To: <CAD=FV=VUoK8SDng6O4-VVq8UZf88b3bSe-hQMht3R2nmYXqMFQ@mail.gmail.com>

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Hi,

> In general you are correct.  You can get by with lots of probe
> deferrals.  I don't personally know of any case where things are
> broken with the current code, but it's really nice to avoid the
> deferrals if possible.

Yes, we all want proper dependencies and ordering, yet deferred probing
is the best we have.

> Given that this is a core SoC i2c bus and is used for _a lot_ of
> external connectivity (including for connecting to the primary
> regulator on most boards), bumping up the priority in the init order
> makes a lot of sense to me.
> 
> This also matches the i2c busses of most other major SoCs.  A selected
> few examples:
> 
> i2c-gpio.c:subsys_initcall(i2c_gpio_init);
> i2c-omap.c:subsys_initcall(omap_i2c_init_driver);
> i2c-s3c2410.c:subsys_initcall(i2c_adap_s3c_init);
> i2c-tegra.c:subsys_initcall(tegra_i2c_init_driver);

They were "lucky" to be around before deferred probing and using
subsys_initcall was always considered a hack. I am not accepting new
users of this hack unless there is really no other solution.

So, NACK, since it doesn't solve a problem.

Regards,

   Wolfram


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  parent reply	other threads:[~2014-09-22 17:13 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-22  7:24 [PATCH] i2c-rk3x: move setup to the earlier subsys initcall Chris Zhong
2014-09-22  7:24 ` Chris Zhong
2014-09-22  7:24 ` Chris Zhong
     [not found] ` <1411370675-27866-1-git-send-email-zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
2014-09-22 16:05   ` Max Schwarz
2014-09-22 16:05     ` Max Schwarz
2014-09-22 16:05     ` Max Schwarz
2014-09-22 16:20     ` Max Schwarz
2014-09-22 16:20       ` Max Schwarz
2014-09-22 16:22     ` Doug Anderson
2014-09-22 16:22       ` Doug Anderson
2014-09-22 16:22       ` Doug Anderson
     [not found]       ` <CAD=FV=VUoK8SDng6O4-VVq8UZf88b3bSe-hQMht3R2nmYXqMFQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-09-22 17:13         ` Wolfram Sang [this message]
2014-09-22 17:13           ` Wolfram Sang
2014-09-22 17:13           ` Wolfram Sang

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