Re: [PATCH] Serial: BUGFIX: uart_resume_port has an omitted condition.

From: MyungJoo Ham
Date: Wed Oct 13 2010 - 02:38:20 EST


On Wed, Oct 13, 2010 at 3:26 PM, Greg KH <gregkh@xxxxxxx> wrote:
> On Wed, Oct 13, 2010 at 02:58:06PM +0900, MyungJoo Ham wrote:
>> When console_suspend_enabled == 0, console_stop() was not called at
>> suspend; thus, it does not need to call console_start() when resume.
>> Besides, calling console_start() without calling console_stop() before
>> had been incurring kernel hang with console_suspend_enabled == 0 in a
>> machine with drivers/serial/samsung.c and s5pc210.
>
> Is this a regression? ÂIf so, from what working kernel? ÂOr has this
> always been this way?
>
> thanks,
>
> greg k-h
>


I don't think this is a regression to the previous version. Logically,
it's matching the console_stop()-console_start() pair.

Such hang in serial and its mitigation is observed in 2.6.36 at
arch/arm/mach-s5pv310 machines. In these machines, it hanged with
console_suspend_enabled == 0 every time.



Cheers!

- MyungJoo

--
MyungJoo Ham (íëì), Ph.D.
Mobile Software Platform Lab,
Digital Media and Communications (DMC) Business
Samsung Electronics
cell: 82-10-6714-2858
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