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

From: Roger
Date: Tue Apr 29 2014 - 23:36:15 EST


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@xxxxxxxx> 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@xxxxxxxx>
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@xxxxxxxx>

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@xxxxxxxxxxx>
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@xxxxxxxxxxx>
---
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
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