Debian 6 , 十个串口为什么只识别到了 6个 剩下四个被禁止了

[麦壳饼]

0.946441] Serial: 8250/16550 driver, 6 ports, IRQ sharing enabled
[ 0.946533] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[ 0.946623] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[ 0.946896] 00:06: ttyS4 at I/O 0x210 (irq = 11) is a 16550A
[ 0.947012] 00:07: ttyS5 at I/O 0x218 (irq = 11) is a 16550A
[ 0.947128] 00:08: ttyS2 at I/O 0x220 (irq = 11) is a 16550A
[ 0.947244] 00:09: ttyS3 at I/O 0x228 (irq = 11) is a 16550A
[ 0.947369] 00:0b: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[ 0.947486] 00:0c: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[ 0.947718] serial 00:0e: disabled
[ 0.947915] serial 00:0f: disabled
[ 0.948094] serial 00:10: disabled
[ 0.948271] serial 00:11: disabled


硬件是 Intel(R) ICH9M LPC Interface Controller - 2919串口