There's a serious typo in the function:
arch/mips/pci/ops-pnx8550.c:write_config_byte()
The parameter passed to the function config_access() is PCI_CMD_CONFIG_READ
instead of PCI_CMD_CONFIG_WRITE. This renders any attempts to write
a single byte to the PCI configuration registers useless.
This problem does not exist for write_config_word() nor write_config_dword().
This problem has been there since kernel v2.6.17 and is still there
as of kernel v2.6.19.1.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>