Re: [PATCH 2/2] [RFC] pl2303 autosuspend

On Mon, 29 Oct 2007, Sarah Sharp wrote:

> On Sat, Oct 27, 2007 at 03:09:02PM -0400, Alan Stern wrote:
> > On Thu, 25 Oct 2007, Sarah Sharp wrote:
> > 
> > > However, I think it will break with kernel swsuspend (and writing "suspend" to
> > > the level sysfs file) if the tty is open.
> > 
> > "swsuspend" is an outmoded term.  Nowadays people talk about "suspend"  
> > and "hibernate" -- I'm guessing you mean "hibernate" here.  This
> > shouldn't cause any problems if the tty is open because no user process
> > could access the tty when the driver's suspend routine is called, since
> > all of userspace gets frozen at the start of a system suspend or
> > hibernation.
> 
> True.  However, you can force the device to suspend by writing 'suspend'
> to the level sysfs file.  If the tty is open and the interface is
> claimed, it will still suspend.  Then a user process can still access
> the tty.  Granted, this wouldn't be normal behavior for most users (who
> would go to the trouble of manually suspending their device when they're
> using it?).

Certainly, if somebody manually suspends a device while trying to use 
it then they will encounter errors.  My point was that there shouldn't 
be any breakage with system suspend or hibernation (what you called 
"swsuspend").

Alan Stern


-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel