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

From: H. Peter Anvin
Date: Fri Jun 06 2014 - 18:28:14 EST


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>^\ÃÃ^@ÃÃ^\Ã^\<8c>ÃÃÃÃ^\<80><80>ÃÃÃÃ<80>Ã<8e>^@ÃÃ^\ÃÃÃ<80>^@<8e>Ã^@Ã<80><80>^\^\Ã^\^@^\ÃÃÃ^@Ã^\ÃÃ^\<80><80>ÃÃ<80>Ã<80>ÃÃÃÃÃ<8e>^\Ã<80>Ã^@Ã<80>ÃÃÃ^@Ã<8e>Ã<80><80><80><80>ÃÃÃ<80>ÃÃ^\Ã^\^\<80>ÃÃÃ^\ÃÃ<8e>^@^\Ã^\^\^\Ã<8e><80>ÃÃ<8e><80>^\^@^@^\^\<8e><8e>^\ÃÃÃ^\<8e>^@^\<80>^@Ã^\Ã^\Ã<80>^@^\^\Ã^\^\Ã^L^@<8e>Ã^\<80>^\^\Ã^\Ã^\Ã
>
> 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


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