Bug 5053 - S3 resume: serial port dead
Summary: S3 resume: serial port dead
Status: REJECTED DUPLICATE of bug 4270
Alias: None
Product: ACPI
Classification: Unclassified
Component: Power-Sleep-Wake (show other bugs)
Hardware: i386 Linux
: P2 normal
Assignee: Russell King
Depends on:
Reported: 2005-08-12 08:13 UTC by Sanjoy Mahajan
Modified: 2005-08-28 10:06 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.13-rc6
Tree: Mainline
Regression: ---


Description Sanjoy Mahajan 2005-08-12 08:13:47 UTC
Distribution: Debian testing
Hardware Environment: TP 600X (has a serial port, which is ttyS0, and a lame
Winmodem, which is ttyS1), connected via a null-modem cable to a Thinkpad 560X

# egrep -i 'serial|tty' /var/log/dmesg
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A

# setserial -a /dev/ttyS0
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

Software Environment: hacked DSDT (see acpidmp in Bug #4989)

Problem Description: After waking, the computer at the other end of the serial
port (it's a TP560X running minicom with params 115200 8N1) no longer gets
dmesgs.  As soon as I run 'setserial -a /dev/ttyS0', they start again.

Steps to reproduce:
Comment 1 Len Brown 2005-08-14 22:13:59 UTC
Did this ever work, or is it a regression with a recent kernel?
Comment 2 Sanjoy Mahajan 2005-08-14 23:07:26 UTC
> Did this ever work, or is it a regression with a recent kernel?

I don't know.  It's the first time I've ever used the serial port on
this laptop (using it for serial-console debugging of Bug #5037, S3
sleep hangs often).  Once I've stressed the current kernel, as part of
debugging Bug #5037, I'll test the serial-port wakeup using earlier
kernels on which S3 sleep/wake worked ( and

Comment 3 Sanjoy Mahajan 2005-08-15 11:43:54 UTC
> Did this ever work, or is it a regression with a recent kernel?

I just tried and, and in both the serial port needs
resetting upon wake (and 'setserial -a /dev/ttyS0' does the trick).
With still earlier kernels, S3 didn't work at all.

Comment 4 Russell King 2005-08-28 10:06:23 UTC

*** This bug has been marked as a duplicate of 4270 ***

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