Re: Garbage on serial console after serial driver loads

[Paul Slootman <paul+nospam@wurtel.net>]

Phil Oester  <kernel@linuxace.com> wrote:
>On Sat, Mar 26, 2005 at 03:10:05PM +0000, Russell King wrote:
>> Doesn't matter.  The problem is that dwmw2's NS16550A patch (from ages
>> ago) changes the prescaler setting for this device so we can use the
>> higher speed baud rates.  This means any programmed divisor (programmed
>> at early serial console initialisation time) suddenly becomes wrong as
>> soon as we fiddle with the prescaler during normal UART initialisation
>> time.
>
>FWIW, I see the same thing here on some Dell Poweredge boxes:
>
>serio: i8042 AUX port at 0x60,0x64 irq 12
>serio: i8042 KBD port at 0x60,0x64 irq 1
>Serial: 8250/16550 driver $Revision: 1.90 $ 8 ports, IRQ sharing disabled
>ttyS0 at I/O 0x3f8 (irq = 4) is a NS16550A
>ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
><garbage>
>
>But intererstingly, on identical boxes, the garbage only appears on
>those hooked up to a PortMaster device - those using a Cyclades never
>display this problem. (???)

We have a variety of Dell rackmount systems, also on Cyclades, and see
this mess everywhere.

I had reported this problem a little while ago, see
http://marc.theaimsgroup.com/?l=linux-kernel&m=111036598927105&w=2
but unfortunately didn't get any response at that time.


Paul Slootman