Re: [PATCH RFC] modpost: Support I2C Aliases from OF tables

From: Wolfram Sang <wsa@the-dreams.de>
To: Javier Martinez Canillas <javierm@redhat.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Michal Marek <michal.lkml@markovi.net>,
	linux-kbuild@vger.kernel.org,
	open list <linux-kernel@vger.kernel.org>,
	linux-renesas-soc@vger.kernel.org,
	Lee Jones <lee.jones@linaro.org>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH RFC] modpost: Support I2C Aliases from OF tables
Date: Wed, 31 Jul 2019 21:44:19 +0200	[thread overview]
Message-ID: <20190731194419.GB4084@kunai> (raw)
In-Reply-To: <0e1b6e0b-1c94-4b00-7fda-c2a303ee3816@redhat.com>

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Hi Javier,

thank you for providing the extra information.

(And Kieran, thanks for the patch!)

> The other option is to remove i2c_of_match_device() and don't make OF match
> to fallback to i2c_of_match_device_sysfs(). This is what happens in the ACPI
> case, since i2c_device_match() just calls acpi_driver_match_device() directly
> and doesn't have a wrapper function that fallbacks to sysfs matching.
> 
> In this case an I2C device ID table would be required if the devices have to
> be instantiated through sysfs. That way the I2C table would be used both for
> auto-loading and also to match the device when it doesn't have an of_node.

That would probably mean that only a minority of drivers will not add an I2C
device ID table because it is easy to add an you get the sysfs feature?

Then we are back again with the situation that most drivers will have
multiple tables. With the minor change that the I2C device id table is
not required anymore by the core, but it will be just very useful to
have? Or?

> If the former is the correct way to solve this then the patch looks good to me.
> 
> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

For this actual patch from Kieran, I'd like to hear an opinion from the
people maintaining modpost. The aproach looks okay to me, yet I can't
tell how "easy" we are with adding new types like 'i2c_of'.

Thanks everyone,

   Wolfram

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