?: Does the s3c2410 serial driver *really* work (suspend/resume)?

Harald Welte laforge at openmoko.org
Tue Apr 22 10:45:00 CEST 2008

On Mon, Apr 21, 2008 at 01:32:33PM -0500, Mike (mwester) wrote:
> I'm asking an opinion question of the kernel gurus...
> Is the s3c2410 serial driver known to work well in regard to flow  
> control and suspend/resume?  Or are we perhaps testing new ground?

what do you mean by 'worl well in regard to flow control'?  I'm pretty
sure all registers get restored to their previous state.

There might be some ordering problem between GPIO resume (MODEM_ON) and
serial resume.

Another note:  Two days ago I was chatting with Alan Cox (who is working
a lot on the serial/tty layer recently) about the problem that serial
drivers busy-spin indefinitely waiting for CTS in case a serial console
is enabled on a port with hardware flow control.

He stated that he thinks there are valid applications where people want
that, but wouldn't mind any platform or machine specific driver that
implemented a timeout or just ignored hw flow control at all when using
the serial console.  A config option to decide on this behaviour would
also be fine, he stated.  Another possible suggestion would have been to
have a seperate set of termios options to be used from the serial
console (separate from the ones that are used by the /dev/ttyS device).

- Harald Welte <laforge at openmoko.org>          	        http://openmoko.org/
Software for the world's first truly open Free Software mobile phone

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