diff --git a/arch/blackfin/include/asm/bfin_serial.h b/arch/blackfin/include/asm/bfin_serial.h
index 7dbc664eab1e2925baf95b8cc949cff65b4a4091..7fd0ec7b5b0f2c9326d0cd4deb0f788b6fadea34 100644
--- a/arch/blackfin/include/asm/bfin_serial.h
+++ b/arch/blackfin/include/asm/bfin_serial.h
@@ -184,7 +184,7 @@ struct bfin_uart_regs {
 #undef __BFP
 
 #ifndef port_membase
-# define port_membase(p) (((struct bfin_serial_port *)(p))->port.membase)
+# define port_membase(p) 0
 #endif
 
 #define UART_GET_CHAR(p)      bfin_read16(port_membase(p) + OFFSET_RBR)
@@ -235,10 +235,10 @@ struct bfin_uart_regs {
 #define UART_SET_DLAB(p)      do { UART_PUT_LCR(p, UART_GET_LCR(p) | DLAB); SSYNC(); } while (0)
 
 #ifndef put_lsr_cache
-# define put_lsr_cache(p, v) (((struct bfin_serial_port *)(p))->lsr = (v))
+# define put_lsr_cache(p, v)
 #endif
 #ifndef get_lsr_cache
-# define get_lsr_cache(p)    (((struct bfin_serial_port *)(p))->lsr)
+# define get_lsr_cache(p) 0
 #endif
 
 /* The hardware clears the LSR bits upon read, so we need to cache