Re: kern/39044: spurious '\n' received from USB-Modems

[Matthias Pfaller <leo%marco.de@localhost>]

The following reply was made to PR kern/39044; it has been noted by GNATS.

From: Matthias Pfaller <leo%marco.de@localhost>
To: M.Drochner%fz-juelich.de@localhost
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%NetBSD.org@localhost, 
 gnats-admin%NetBSD.org@localhost, netbsd-bugs%NetBSD.org@localhost
Subject: Re: kern/39044: spurious '\n' received from USB-Modems
Date: Fri, 04 Jul 2008 15:18:04 +0200

 Matthias Drochner wrote:
 > leo%marco.de@localhost said:
 >> Removing the
 >>                             (*rint)('\n', tp);
 >>    line from ucom.c doesn't seem to harm
 > 
 > Maybe, but to understand what's going on it would help
 > to know which of the 3 possible conditions trigger this.
 > (status == USBD_CANCELLED || status == USBD_IOERROR ||
 > sc->sc_dying)
 
 I inserted:
                  logprintf("status = %d, sc->sc_dying = %d\n", status,
                          sc->sc_dying);
 
 The result is:
      Jul  1 14:05:49 joghurt /netbsd: status = 6, sc->sc_dying = 0
 
 status = 6 is USBD_CANCELLED.
 
 Some more investigation showed (and a mail from Matthias Drochner) 
 showed, that it is ucomclose calling ucom_cleanup that triggers the 
 spurious \n. The \n is inserted into the tty queue at device close time 
 and delivered, when I open the device. Is there any reason to to insert 
 the \n into the queue when doing a device close?
 
 Regards, Matthias
 -- 
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