[20100713]Android VOLD 和SDIO冲突问题

开发板有两个MMC接口，一个挂载SD卡，另外一个挂载SDIO接口，当同时工作，启动Android时Vold会崩溃导致无法启动。

错误代码如下：

# logcat

I/DEBUG   (  810): debuggerd: Jun  9 2010 21:50:44

I/vold    (  809): Android Volume Daemon version 2.0

I/vold    (  809): New MMC card 'SD01G' (serial 2685562678) added @ /devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:e624

I/vold    (  809): Disk (blkdev 179:0), 1984000 secs (968 MB) 1 partitions

I/vold    (  809): New blkdev 179.0 on media SD01G, media path /devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:e624, Dpp 1

I/vold    (  809): Partition (blkdev 179:1), 1983171 secs (968 MB) type 0xb

I/vold    (  809): New blkdev 179.1 on media SD01G, media path /devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:e624, Dpp 0

I/vold    (  809): Evaluating dev '/devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:e624/block/mmcblk0' for mountable filesystems for '/sdcard'

I/vold    (  809): Aborting start of /sdcard (bootstrap = 1)

I/vold    (  809): Volmgr not ready to handle device

I/DEBUG   (  810): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

I/DEBUG   (  810): Build fingerprint: 'ky6410/ky6410/ky6410/:2.1-update1/ECLAIR/eng.kyon.20100609.214617:eng/test-keys'

I/DEBUG   (  810): pid: 809, tid: 809  >>> /system/bin/vold <<<

I/DEBUG   (  810): signal 11 (SIGSEGV), fault addr 00000000

I/DEBUG   (  810):  r0 00000000  r1 00020000  r2 80808080  r3 00000000

I/DEBUG   (  810):  r4 000111d8  r5 bef185bc  r6 bef185a8  r7 bef187c0

I/DEBUG   (  810):  r8 00000000  r9 00000000  10 00000000  fp 00000000

I/DEBUG   (  810):  ip 00011324  sp bef18588  lr 0000a88d  pc afe0e7f4  cpsr 40000010

I/DEBUG   (  810):          #00  pc 0000e7f4  /system/lib/libc.so

I/DEBUG   (  810):          #01  pc 0000a88a  /system/bin/vold

I/DEBUG   (  810):          #02  pc 0000aa30  /system/bin/vold

I/DEBUG   (  810):          #03  pc 0000ab0e  /system/bin/vold

I/DEBUG   (  810):          #04  pc 00009844  /system/bin/vold

I/DEBUG   (  810):          #05  pc 0000c2c6  /system/lib/libc.so

I/DEBUG   (  810):          #06  pc b00018aa  /system/bin/linker

查看Vold的源码，Vold使用while循环读取SYSFS_CLASS_MMC_PATH，估计读到SD卡后会继续去读取SDIO设备，导致fault addr 00000000

/*

 * Bootstrap our mmc information.

 */

int mmc_bootstrap()

{

    DIR *d;

    struct dirent *de;

    if (!(d = opendir(SYSFS_CLASS_MMC_PATH))) {

        LOG_ERROR("Unable to open '%s' (%s)", SYSFS_CLASS_MMC_PATH,

                  strerror(errno));

        return -errno;

    }

    while ((de = readdir(d))) {

        char tmp[255];

        if (de->d_name[0] == '.')

            continue;

        sprintf(tmp, "%s/%s", SYSFS_CLASS_MMC_PATH, de->d_name);

        if (mmc_bootstrap_controller(tmp)) {

            LOG_ERROR("Error bootstrapping controller '%s' (%s)", tmp,

                      strerror(errno));

        }

    }

    closedir(d);

    return 0;

}

正好网上有人提供了patch，一次mmc_bootstrap_controller后退出

--- a/system/core/vold/mmc.c    2009-07-02 16:15:08.000000000 -0400

+++ b/system/core/vold/mmc.c    2009-07-17 10:35:02.000000000 -0400

@@ -54,8 +54,14 @@

             continue;

         sprintf(tmp, "%s/%s", SYSFS_CLASS_MMC_PATH, de->d_name);

-        if (mmc_bootstrap_controller(tmp))

+        if (mmc_bootstrap_controller(tmp)) {

             LOG_ERROR("Error bootstrapping controller '%s' (%m)",

tmp);

+        }

+        else {

+            //a controller has already been bootstrapped, lets stop

trying to get more

+            //TODO: hack fix to get around segfault on boostrapping

sdio card connected to mmc bus

+            break;

+        }

     }

     closedir(d);