Hi,
[v1 -> v2]
Fix a compile warning with data convert.
[v1 log]
When running setserial, application issue a TIOCGSERIAL iotcl to get serial
setting, then update
serial setting with TIOCSSERIAL ioctl. It always failed with TIOCSSERIAL ioctl,
for application
pass 0xffffffff for iomem_base in serial_struct to kernel.
On 32bit rootfs & 64bit kernel, compat_ioctl use 0xffffffff as a magic number
to mark invalid pointer
for iomem_base in serial_struct when truncating a 64bit pointer into 32bit.
Serial driver need recognize this invalid pointer when parsing serial_struct
from userspace.
Thanks
Jiang Lu
