problem with high memory support

[Kodandaram, Harish]

Hello all,

I have x86 based board with 1GB RAM, a 16MB TE28F128J3C flash and  I am
implementing flash driver for the same.
If I disable CONFIG_HIGHMEM_4G option my driver works correctly. But with
CONFIG_HIGHMEM_4G option enabled i'm facing problem while mounting
filesystem. 

First I want know whether it's advised to enable CONFIG_HIGHMEM support with
1 GB RAM? If Yes, then do we have to perform any additional tasks,
especially when IO devices address high memory through PCI space.

Thanking You in advance

Regards
Harish