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From: Thierry Reding <thierry.reding@gmail.com>
To: Jean Delvare <jdelvare@suse.de>
Cc: Kyungmin Park <kyungmin.park@samsung.com>,
	Kukjin Kim <kgene.kim@samsung.com>,
	Seung-Woo Kim <sw0312.kim@samsung.com>,
	Alexander Graf <agraf@suse.de>,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm/exynos: Fix PTN3460 dependency
Date: Wed, 21 May 2014 17:51:02 +0200	[thread overview]
Message-ID: <20140521155059.GP2014@ulmo> (raw)
In-Reply-To: <20140520111525.3a62e25d@endymion.delvare>


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On Tue, May 20, 2014 at 11:15:25AM +0200, Jean Delvare wrote:
> The following configuration options combination:
> 
> CONFIG_DRM_EXYNOS_DP=y
> CONFIG_DRM_PTN3460=m
> 
> currently leads to the following linker failure:
> 
> drivers/built-in.o: In function `exynos_drm_attach_lcd_bridge':
> .../drivers/gpu/drm/exynos/exynos_dp_core.c:1004:
> undefined reference to `ptn3460_init'
> 
> This is because ptn3460_init can't be implemented in a module while
> its caller is built into the kernel. So add the proper dependency in
> Kconfig so that the above can't happen.
> 
> I moved DRM_PTN3460 earlier in Kconfig, next to the I2C helper module
> section, so that the user has a chance to select it before moving to
> the Exynos-specific section.
> 
> IMHO the proper way to solve the problem would be to turn ptn3460 into
> a clean I2C driver, similar to the other I2C helper chip drivers. It's
> the only way to not sink into impossible-to-guess dependencies. Then
> ptn3460 could even be moved together with the other I2C helper chip
> drivers.

FWIW, various ideas have been discussed to solve this problem. The most
recent agreement I think was to create a registry for bridge drivers to
register DRM bridge objects against and allow drivers to look them up.
That way we can get rid of the various *_init() functions that currently
need to be called directly from within DRM drivers.

I'm not aware of anybody working on this currently, hence I think this
is an appropriate fix in the meantime:

Reviewed-by: Thierry Reding <treding@nvidia.com>

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  reply	other threads:[~2014-05-21 15:53 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-20  9:15 [PATCH] drm/exynos: Fix PTN3460 dependency Jean Delvare
2014-05-21 15:51 ` Thierry Reding [this message]
2014-05-22 11:27   ` Inki Dae

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