dm 8168 SD卡不支持热拔插 问题

mmcblk0: error -110 sending status comand
mmcblk0: error -110 sending read/write command, response 0x0, card status 0x0
mmcblk0: error -110 transferring data, sector 64, nr 1, card status 0x0
mmcblk0: error -110 requesting status
func is mmc_sd_num_wr_blocks, file is drivers/mmc/card/block.c[187] <<<-----
end_request: I/O error, dev mmcblk0, sector 64
Buffer I/O error on device mmcblk0p1, logical block 1
lost page write due to I/O error on mmcblk0p1
板子上SD卡只能插入一次，拔出SD卡后 df 查看不发生变化，但是文件不能访问，再次插入SD卡会报错
root@ti81xx:~# df -h
Filesystem                Size      Used Available Use% Mounted on
ubi0:rootfs             430.0M     55.7M    374.2M  13% /
devtmpfs                225.2M    172.0K    225.0M   0% /dev
none                    225.3M         0    225.3M   0% /dev/shm
tmpfs                    16.0M     60.0K     15.9M   0% /var/volatile
tmpfs                    16.0M         0     16.0M   0% /media/ram
/dev/sda                916.9G     67.0G    803.3G   8% /zigsun
/dev/mmcblk0p2            7.3G      3.7G      3.3G  53% /media/mmcblk0p2
/dev/mmcblk0p1           69.5M     45.3M     24.2M  65% /media/mmcblk0p1