Dear All,
I meet a wired UART problem on linux-2.6 with MPC8241 chip.
My Environment is as following:
CPU: MPC8241
Linux: 2.6.12.3
COM1 offset: 0x4500, COM2 offset: 0x4600
When I booting my rootfs, it hangs at following message:
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem) readonly.
Freeing unused kernel memory: 104k init
EXT2-fs warning: checktime reached, running e2fsck is recommended
I had add printk in tty_write() of drivers/char/tty_io.c, the message from
rootfs have printed.
The conclusion is that message can be printed by printk() in linux kernel,
but can't be printed by printf() in user mode. I think it must be something
wrong for my UART configurations, does anybody know it??
Best Regards,
Johnson Cheng
Johnson,
You know what? I've had the exact same problem only day or two ago. I
think the mail subject was "serial console" or something similar. Have
a read at it.
BTW, My problem was with interrupt setting.
Daniel.
On 8/2/05, JohnsonCheng [off-list ref] wrote:
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Dear All,
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I meet a wired UART problem on linux-2.6 with MPC8241 chip.
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My Environment is as following:=20
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CPU: MPC8241
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Linux: 2.6.12.3
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COM1 offset: 0x4500, COM2 offset: 0x4600
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When I booting my rootfs, it hangs at following message:
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RAMDISK: Compressed image found at block 0
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VFS: Mounted root (ext2 filesystem) readonly.
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Freeing unused kernel memory: 104k init
=20
EXT2-fs warning: checktime reached, running e2fsck is recommended
=20
=20
=20
I had add printk in tty_write() of drivers/char/tty_io.c, the message fro=
m
rootfs have printed.
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The conclusion is that message can be printed by printk() in linux kernel=
,
but can't be printed by printf() in user mode. I think it must be somethi=
ng
wrong for my UART configurations, does anybody know it??
=20
=20
=20
=20
=20
Best Regards,
=20
Johnson Cheng
_______________________________________________
Linuxppc-embedded mailing list
Linuxppc-embedded@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-embedded
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--=20
Daniel
Actually, I had reviews all article about "serial console", just know I have
to use LEVEL for interrupt, not EDGE. Unfortunately the default interrupt
setting for kernel is with LEVEL, IRQ_SENSE_LEVEL, I think I don't need to
modify it.
But I found I add ASYNC_SKIP_TEST flag to UART in sandpoint.h can fix my
problem.
Thanks,
Johnson Cheng
-----Original Message-----
From: linuxppc-embedded-bounces@ozlabs.org
[mailto:linuxppc-embedded-bounces@ozlabs.org] On Behalf Of Daniel Ann
Sent: Wednesday, August 03, 2005 8:22 AM
To: JohnsonCheng
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: A PPC kernel issue with UART ??
Johnson,
You know what? I've had the exact same problem only day or two ago. I
think the mail subject was "serial console" or something similar. Have
a read at it.
BTW, My problem was with interrupt setting.
Daniel.
On 8/2/05, JohnsonCheng [off-list ref] wrote:
Dear All,
I meet a wired UART problem on linux-2.6 with MPC8241 chip.
My Environment is as following:
CPU: MPC8241
Linux: 2.6.12.3
COM1 offset: 0x4500, COM2 offset: 0x4600
When I booting my rootfs, it hangs at following message:
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem) readonly.
Freeing unused kernel memory: 104k init
EXT2-fs warning: checktime reached, running e2fsck is recommended
I had add printk in tty_write() of drivers/char/tty_io.c, the message from
rootfs have printed.
The conclusion is that message can be printed by printk() in linux kernel,
but can't be printed by printf() in user mode. I think it must be
something
wrong for my UART configurations, does anybody know it??
Best Regards,
Johnson Cheng
_______________________________________________
Linuxppc-embedded mailing list
Linuxppc-embedded@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-embedded
--
Daniel
_______________________________________________
Linuxppc-embedded mailing list
Linuxppc-embedded@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-embedded