Garbage characters on serial console (Linus "next")

Garbage characters on serial console (Linus "next")

[Tony Luck]

Pulled from Linus' "next" branch (HEAD =
2b03adc1911d1c84cb7fad8b424234f589547cb3)
and built & booted on ia64.  I see a lot of random characters on the
serial console. Suspiciously starting right after reporting the serial
line has been found.

Here's what the output looks like when I "vi" the saved file:

io scheduler noop registered^M
io scheduler deadline registered^M
io scheduler cfq registered (default)^M
pci_hotplug: PCI Hot Plug PCI Core version: 0.5^M
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled^M
00:02: ttyS0 at I/O 0x3f8 (irq = 44, base_baud = 115200) is a 16550A^M
<80>^\þÇ^@üþ^\à^\<8c>àüðð^\<80><80>üðøþ<80>à<8e>^@üà^\àðÀ<80>^@<8e>à^@à<80><80>^\^\ÿ^\^@^\þþà^@à^\ðð^\<80><80>üþ<80>ü<80>þðøüà<8e>^\à<80>ð^@ÿ<80>üðà^@à<8e>ð<80><80><80><80>þðþ<80>üþ^\à^\^\<80>þÇü^\øà<8e>^@^\à^\^\^\ð<8e><80>ðà<8e><80>^\^@^@^\^\<8e><8e>^\àþþ^\<8e>^@^\<80>^@þ^\ÿ^\à<80>^@^\^\ø^\^\à^L^@<8e>ð^\<80>^\^\ü^\ø^\ÿ

Output continues with alternating blocks of legible text and garbage.
System eventually boots (with a legible "login:" prompt).

-Tony

Re: Garbage characters on serial console (Linus "next")

[H. Peter Anvin]

On 06/06/2014 03:07 PM, Tony Luck wrote:
> Pulled from Linus' "next" branch (HEAD =
> 2b03adc1911d1c84cb7fad8b424234f589547cb3)
> and built & booted on ia64.  I see a lot of random characters on the
> serial console. Suspiciously starting right after reporting the serial
> line has been found.
> 
> Here's what the output looks like when I "vi" the saved file:
> 
> io scheduler noop registered^M
> io scheduler deadline registered^M
> io scheduler cfq registered (default)^M
> pci_hotplug: PCI Hot Plug PCI Core version: 0.5^M
> Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled^M
> 00:02: ttyS0 at I/O 0x3f8 (irq = 44, base_baud = 115200) is a 16550A^M
> <80>^\þÇ^@üþ^\à^\<8c>àüðð^\<80><80>üðøþ<80>à<8e>^@üà^\àðÀ<80>^@<8e>à^@à<80><80>^\^\ÿ^\^@^\þþà^@à^\ðð^\<80><80>üþ<80>ü<80>þðøüà<8e>^\à<80>ð^@ÿ<80>üðà^@à<8e>ð<80><80><80><80>þðþ<80>üþ^\à^\^\<80>þÇü^\øà<8e>^@^\à^\^\^\ð<8e><80>ðà<8e><80>^\^@^@^\^\<8e><8e>^\àþþ^\<8e>^@^\<80>^@þ^\ÿ^\à<80>^@^\^\ø^\^\à^L^@<8e>ð^\<80>^\^\ü^\ø^\ÿ
> 
> Output continues with alternating blocks of legible text and garbage.
> System eventually boots (with a legible "login:" prompt).
> 

Looks like the baud rate changed...

	-hpa