Re: [PATCH] mmc: rtsx: usb backend needs LED support

From: Arnd Bergmann <arnd@arndb.de>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: micky <micky_ching@realsil.com.cn>, Chris Ball <chris@printf.net>,
	Lee Jones <lee.jones@linaro.org>,
	Samuel Ortiz <sameo@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	devel@linuxdriverproject.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	linux-mmc <linux-mmc@vger.kernel.org>,
	Roger <rogerable@realtek.com>, Wei WANG <wei_wang@realsil.com.cn>
Subject: Re: [PATCH] mmc: rtsx: usb backend needs LED support
Date: Tue, 29 Apr 2014 14:46:43 +0200	[thread overview]
Message-ID: <20686823.1FvTzs9RAn@wuerfel> (raw)
In-Reply-To: <CAPDyKFpJrrviaZo_L8MkLF=v7DqGEVj9=uSNsNtU-FXNwu-MmQ@mail.gmail.com>

On Tuesday 29 April 2014 13:05:15 Ulf Hansson wrote:
> On 29 April 2014 11:45, Arnd Bergmann <arnd@arndb.de> wrote:
> > drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_remove':
> > :(.text+0x806480): undefined reference to `led_classdev_unregister'
> > drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_probe':
> > :(.text+0x806708): undefined reference to `led_classdev_register'
> >
> > This adds an explicit dependency in Kconfig
> 
> I think the proper solution is to fix the dependency in the driver code instead.
> 
> There are already some ifdefs hackery for making it optional to use
> leds, apparently that's not working properly.
> 

Ah, right, I misinterpreted the bug. Here is a new version:

8<---------
>From 5b5588f8c9b8ded8b296fd32d87b2d118e548a29 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 29 Apr 2014 11:41:40 +0200
Subject: [PATCH] mmc: rtsx: usb backend needs LED support

Building the rtsx USB driver uses the LED classdev base
support if available, but that fails if the classdev
is a module and the MMC driver is built-in, leading to this
link error.

drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_remove':
:(.text+0x806480): undefined reference to `led_classdev_unregister'
drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_probe':
:(.text+0x806708): undefined reference to `led_classdev_register'

This adds an explicit dependency in Kconfig to ensure that
the MMC driver has to be a module if LEDS_CLASS is a module,
but still allows it to be built-in if LEDS_CLASS is either
disabled or built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 92d91fe..68da9b8 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -696,6 +696,7 @@ config MMC_REALTEK_PCI
 config MMC_REALTEK_USB
 	tristate "Realtek USB SD/MMC Card Interface Driver"
 	depends on MFD_RTSX_USB
+	depends on m || LEDS_CLASS!=m
 	help
 	  Say Y here to include driver code to support SD/MMC card interface
 	  of Realtek RTS5129/39 series card reader

