Message-ID: <1434982982.2524.10.camel@tiscali.nl>
Subject: Re: [PATCH 4.0 050/105] i2c: hix5hd2: Fix modalias to make module
 auto-loading work
From: Paul Bolle <pebolle@tiscali.nl>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org, Axel Lin <axel.lin@ingics.com>,
        Zhangfei Gao <zhangfei.gao@linaro.org>,
        Wolfram Sang <wsa@the-dreams.de>
Date: Mon, 22 Jun 2015 16:23:02 +0200
In-Reply-To: <20150619203559.674642625@linuxfoundation.org>
References: <20150619203558.187802739@linuxfoundation.org>
	 <20150619203559.674642625@linuxfoundation.org>
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On Fri, 2015-06-19 at 13:35 -0700, Greg Kroah-Hartman wrote:
> Make the modalias match driver name, this is required to make module
> auto-loading work.
> 
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> Acked-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> ---
>  drivers/i2c/busses/i2c-hix5hd2.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/drivers/i2c/busses/i2c-hix5hd2.c
> +++ b/drivers/i2c/busses/i2c-hix5hd2.c
> @@ -554,4 +554,4 @@ module_platform_driver(hix5hd2_i2c_drive
>  MODULE_DESCRIPTION("Hix5hd2 I2C Bus driver");
>  MODULE_AUTHOR("Wei Yan <sledge.yanwei@huawei.com>");
>  MODULE_LICENSE("GPL");
> -MODULE_ALIAS("platform:i2c-hix5hd2");
> +MODULE_ALIAS("platform:hix5hd2-i2c");

How does this work?

My current understanding is that for module auto-loading to work with
the platform: prefix one needs a matching platform_device (ie, a struct
platform_device with .name being "hix5hd2-i2c"). And I couldn't spot
where that platform_device is created in 4.0 or v4.1.

Does matching platform_driver.driver.name (which is what this patch
appears to do) also enable module auto-loading? That would mean there's
another, even less obvious, mechanism at work here.

Thanks,


Paul Bolle
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