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

[Roger <rogerable@realtek.com>]

On 04/29/2014 08:46 PM, Arnd Bergmann wrote:
> 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
>
> .
>

I think Ulf's idea is to fix the bug by modifying the .c files.
I really found the problem of my ifdef hackery and it should do 
something similar in sdhci.c as:

From: Roger Tseng <rogerable@realtek.com>
Date: Wed, 30 Apr 2014 11:11:25 +0800
Subject: [PATCH] mmc: rtsx: fix possible linking error if built-in

rtsx_usb_sdmmc module uses the LED classdev if available, but the code 
failed
to consider the situation that it is built-in and the LED classdev is a 
module,
leading to following linking error:

   LD      init/built-in.o
drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_remove':
rtsx_usb_sdmmc.c:(.text+0x2a018e): undefined reference to 
`led_classdev_unregister'
drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_probe':
rtsx_usb_sdmmc.c:(.text+0x2a197e): undefined reference to 
`led_classdev_register'

Fix by excluding such condition when defining macro RTSX_USB_USE_LEDS_CLASS.

Signed-off-by: Roger Tseng <rogerable@realtek.com>
---
  drivers/mmc/host/rtsx_usb_sdmmc.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c 
b/drivers/mmc/host/rtsx_usb_sdmmc.c
index e11fafa..38bdda5 100644
--- a/drivers/mmc/host/rtsx_usb_sdmmc.c
+++ b/drivers/mmc/host/rtsx_usb_sdmmc.c
@@ -34,7 +34,8 @@
  #include <linux/mfd/rtsx_usb.h>
  #include <asm/unaligned.h>

-#if defined(CONFIG_LEDS_CLASS) || defined(CONFIG_LEDS_CLASS_MODULE)
+#if defined(CONFIG_LEDS_CLASS) || (defined(CONFIG_LEDS_CLASS_MODULE) && \
+       defined(CONFIG_MMC_REALTEK_USB_MODULE))
  #include <linux/leds.h>
  #include <linux/workqueue.h>
  #define RTSX_USB_USE_LEDS_CLASS

Best regards,
Roger Tseng