FAQ: [#7020] console serial port is not working after resume from hibernate(2012)

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[#7020] console serial port is not working after resume from hibernate

Submitted By: Patrik Kluba

Open Date

2012-03-22 09:45:09    

Priority:

Medium     Assignee:

steven miao

Status:

Open     Fixed In Release:

N/A

Found In Release:

2011R1     Release:

2011R1

Category:

N/A     Board:

Custom

Processor:

ALL     Silicon Revision:

Is this bug repeatable?:

Yes     Resolution:

Rejected

Uboot version or rev.:

    Toolchain version or rev.:

4.3.5

App binary format:

N/A     

Summary: console serial port is not working after resume from hibernate

Details:

 

When the 'no_console_suspend' kernel command line parameter was given OR the given serial port is configured to wake up the system from sleep, the serial port does not get reinitialized when returning from hibernate, leaving it in a non-working state.

 

http://lxr.linux.no/#linux+v3.3/drivers/tty/serial/serial_core.c#L1873

If device_may_wakeup() returns true, the ASYNCB_SUSPENDED does not get set.

 

http://lxr.linux.no/#linux+v3.3/drivers/tty/serial/serial_core.c#L1973

http://lxr.linux.no/#linux+v3.3/drivers/tty/serial/serial_core.c#L1981

These are the conditionals calling port-startup() depends on.

 

Maybe the above is correct, and leaving the serial port unconfigured is just an unwanted side-effect which applies only for Blackfin. I have failed to find a nice solution. Any ideas?

 

Follow-ups

 

--- Sonic Zhang                                              2012-05-04 04:55:08

Which blackfin chip do you test?

 

--- steven miao                                              2012-08-09 04:35:55

with no_console_suspend=1, serial_core will not touch serial port during suspend

and resume, for hibernate the serial port registers will lost, it will be

unavailable after resume. This no_console_suspend is just for debug.

 

 

 

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