Re: [PATCH 03/18] mtd: dataflash: Export OF module alias information

From: Javier Martinez Canillas <javier@osg.samsung.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: linux-kernel@vger.kernel.org, Mark Brown <broonie@kernel.org>,
	linux-mtd@lists.infradead.org,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH 03/18] mtd: dataflash: Export OF module alias information
Date: Fri, 21 Aug 2015 00:57:54 +0200	[thread overview]
Message-ID: <55D65B72.2050006@osg.samsung.com> (raw)
In-Reply-To: <20150820223440.GC81844@google.com>

Hello Brian,

On 08/21/2015 12:34 AM, Brian Norris wrote:
> On Fri, Aug 21, 2015 at 12:13:34AM +0200, Javier Martinez Canillas wrote:
>> So this patch really is a no-op right now and is not fixing anything.
>> As long as the driver has a MODULE_DEVICE_TABLE(spi,...), things will
> 
> This driver does not have a MODULE_DEVICE_TABLE() at all, nor does it
> use spi_device_id. So, it is currently broken for the module use case.
>

That is correct but also that does not mean that this patch will fix
module autoloading right now. It will though once the SPI core is
changed to report a OF type module alias.

So what about something along this lines?

mtd: dataflash: Export OF module alias information

The SPI core currently reports the MODALIAS uevent as "spi:<modalias>"
even for SPI devices that were registered by OF.

That means the OF module alias exported by MODULE_OF_TABLE(of,...) is
currently not used and user-space has no way to autoload this module.

But is still a good practice to add the OF module alias information
into the kernel module even when currently is unused so once the SPI
core is changed to report a correct OF modalias uevent, module
autoloading will be working for this driver.

>> work without a MODULE_DEVICE_TABLE(of,...).
> 
> Brian
> 

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America