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Re: Ack! Only 4 uarts with FC6!



On Fri, 2006-10-27 at 20:39 -0400, Dave Jones wrote: 
> On Thu, Oct 26, 2006 at 11:04:05PM -0700, Brian Mury wrote:
>  > On Thu, 2006-10-26 at 17:44 -0400, Tom Horsley wrote:
>  > > Lo these many years, the kernel parameter 8250.nr_uarts=9 has
>  > 
>  > I have the same problem here. My motherboard has 2 RS232 ports, and I
>  
> Even if you boot with the parameter Tom mentioned ?

Good question - I didn't try it. I didn't need to provide any kernel
paramters with FC1, FC2, FC3, FC4, or FC5... it always "just worked".
Well, actually, with earlier versions I did have to put some lines
in /etc/rc.d/rc.local of the form:

"setserial /dev/ttyS4 port 0xa000 irq 12 uart 16550a baud_base 115200 ^fourport"

but I think the need for that was eliminated with udev, IIRC.

I'll try it and see what happens, back in a minute after I reboot...

Ok, I'm back... that worked. I can access all 6 serial ports.

I also just discovered that without that kernel parameter, there are 4
ports in /dev, but only the first two (the motherboard ones) are usable
- the other two aren't. *With* the kernel parameter, I not only see all
6 ports, I can use them all.

Ok, I'm curious. Is the 4 ports just a default number that is used
regardless of whether or not they actually exist? Why aren't the 3rd and
4th ports that are in /dev without the kernel parameter usable (since
all it seems to do is tell the kernel how many ports to use)? And why do
I need this at all since I didn't need it in FC 1 through 5?

I'm happy since my problem is solved, but just in case it's of any use
to anyone:

>From /var/log/messages, booting without the kernel parameter:

Oct 25 01:29:00 localhost kernel: Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
Oct 25 01:29:00 localhost kernel: serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Oct 25 01:29:00 localhost kernel: serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
Oct 25 01:29:00 localhost kernel: 00:0a: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Oct 25 01:29:00 localhost kernel: 00:0b: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
Oct 25 01:29:00 localhost kernel: ACPI: PCI Interrupt Link [APC4] enabled at IRQ 19
Oct 25 01:29:00 localhost kernel: ACPI: PCI Interrupt 0000:02:04.0[A] -> Link [APC4] -> GSI 19 (level, high) -> IRQ 177
Oct 25 01:29:00 localhost kernel: 0000:02:04.0: ttyS2 at I/O 0xa000 (irq = 177) is a 16550A
Oct 25 01:29:00 localhost kernel: 0000:02:04.0: ttyS3 at I/O 0xa400 (irq = 177) is a 16550A
Oct 25 01:29:00 localhost kernel: ACPI: PCI Interrupt 0000:02:04.1[A] -> Link [APC4] -> GSI 19 (level, high) -> IRQ 177
Oct 25 01:29:00 localhost kernel: Couldn't register serial port 0000:02:04.1: -28

With the kernel parameter:

Oct 27 22:35:26 localhost kernel: Serial: 8250/16550 driver $Revision: 1.90 $ 6 ports, IRQ sharing enabled
Oct 27 22:35:26 localhost kernel: serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Oct 27 22:35:26 localhost kernel: serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
Oct 27 22:35:26 localhost kernel: 00:0a: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Oct 27 22:35:26 localhost kernel: 00:0b: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
Oct 27 22:35:26 localhost kernel: ACPI: PCI Interrupt Link [APC4] enabled at IRQ 19
Oct 27 22:35:26 localhost kernel: ACPI: PCI Interrupt 0000:02:04.0[A] -> Link [APC4] -> GSI 19 (level, high) -> IRQ 177
Oct 27 22:35:26 localhost kernel: 0000:02:04.0: ttyS4 at I/O 0xa000 (irq = 177) is a 16550A
Oct 27 22:35:26 localhost kernel: 0000:02:04.0: ttyS5 at I/O 0xa400 (irq = 177) is a 16550A
Oct 27 22:35:26 localhost kernel: ACPI: PCI Interrupt 0000:02:04.1[A] -> Link [APC4] -> GSI 19 (level, high) -> IRQ 177
Oct 27 22:35:26 localhost kernel: 0000:02:04.1: ttyS2 at I/O 0xa800 (irq = 177) is a 16550A
Oct 27 22:35:26 localhost kernel: 0000:02:04.1: ttyS3 at I/O 0xac00 (irq = 177) is a 16550A

And from lspci -v:

02:04.0 Serial controller: Lava Computer mfg Inc Quattro-PCI A (prog-if 02 [16550])
        Flags: slow devsel, IRQ 177
        I/O ports at a000 [size=8]
        I/O ports at a400 [size=8]

02:04.1 Serial controller: Lava Computer mfg Inc Quattro-PCI B (prog-if 02 [16550])
        Flags: slow devsel, IRQ 177
        I/O ports at a800 [size=8]
        I/O ports at ac00 [size=8]



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