UART prints very slow

2 messages, 2 authors, 2003-09-30 · open the first message on its own page

UART prints very slow

From: Yuxiao Xi <hidden>
Date: 2003-09-30 02:07:23

Hello,all,
    I am developing my board with CPU MPC8240 and a UART ST16C2552.
I use MontaVista Linux 2.1. Now I have successfully logged in the
shell.But there is a question that I can't resolve:( I am sure that the
UART is successfully initialized except that ST16C2552 is detected as
ST16650.I debugged the UART interrupt and the printk info showed that it
was OK.

QUESTION: when I input commands such as 'ls', 'cd /dev' on the shell,
the characters of these commands are printed very slow on the screen
and the command execution results as well. I think these commands and
their execution results are printed through UART interrupt.Is MPC8240
interrupt ACK so slow? BTW: while system booting,the UART prints very
quickly in polling print mode.

����������������Yuxiao Xi
����������������xiyuxiao@harbournetworks.com
��������������������2003-09-30

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: UART prints very slow

From: Mark A. Greer <hidden>
Date: 2003-09-30 18:48:02

Interrupt problem.  Double check the irq you specified in the uart setup
stuff.

Mark
--

Yuxiao Xi wrote:
Hello,all,
   I am developing my board with CPU MPC8240 and a UART ST16C2552.
I use MontaVista Linux 2.1. Now I have successfully logged in the
shell.But there is a question that I can't resolve:( I am sure that the
UART is successfully initialized except that ST16C2552 is detected as
ST16650.I debugged the UART interrupt and the printk info showed that it
was OK.

QUESTION: when I input commands such as 'ls', 'cd /dev' on the shell,
the characters of these commands are printed very slow on the screen
and the command execution results as well. I think these commands and
their execution results are printed through UART interrupt.Is MPC8240
interrupt ACK so slow? BTW: while system booting,the UART prints very
quickly in polling print mode.

¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡Yuxiao Xi
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡xiyuxiao@harbournetworks.com
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2003-09-30





** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
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