[U-Boot] u-boot hangs on panda board after some time

[Vivi]

On TI panda board, stay in u-boot and do nothing in 30 minutes, then
try to get mmc info or reset, u-boot will hang.

Bellow is the error log:
--
Panda # printenv

baudrate=115200
bootcmd=if mmc rescan ${mmcdev}; then if run loadbootscript; then run
bootscript; else if run loaduimage; then run mmcboot; fi; i
bootdelay=3
bootscript=echo Running bootscript from mmc${mmcdev} ...; source ${loadaddr}


console=ttyS2,115200n8
loadaddr=0x82000000
loadbootscript=fatload mmc ${mmcdev} ${loadaddr} boot.scr
loaduimage=fatload mmc ${mmcdev} ${loadaddr} uImage
mmcargs=setenv bootargs console=${console} vram=${vram}
root=${mmcroot} rootfstype=${mmcrootfstype}


mmcboot=echo Booting from mmc${mmcdev} ...; run mmcargs; bootm ${loadaddr}
mmcdev=0
mmcroot=/dev/mmcblk0p2 rw
mmcrootfstype=ext3 rootwait
usbtty=cdc_acm
vram=16M

Environment size: 686/262140 bytes


Panda # mmcinfo

--

Thanks and best regards,
Vivi Li