On kzm9g board (rmobile SoC), autoboot fails if serial console cable is not
connected. When serial cable is not connected, serial error occurs and
some garbage comes in data register.
sh_serial_tstc() in serial_sh.c does not check error status and misunderstand
there is some input data. It is the reason that autoboot fails.
This patch adds checking error status in sh_serial_tstc().
This patch is based on v2013.01-rc1 tag of u-boot master git.
Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>