From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============7047336494910838222==" MIME-Version: 1.0 From: Denis Kenzior Subject: Re: Dealing with modem hangs Date: Mon, 24 Mar 2014 16:04:54 -0500 Message-ID: <53309DF6.9000003@gmail.com> In-Reply-To: List-Id: To: ofono@ofono.org --===============7047336494910838222== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Hi Yevhen, On 03/24/2014 03:45 PM, Yevhen Kyriukha wrote: > I use 3G modems connected to unattended terminals for a long time. > I use ofono for managing 2G connections. > > All this time I'm suffering from modem hangs: during establishing 2G > connection modem may hang, i.e. it stops reacting on AT commands to > specific port. > I'd tested a lot of modems of different brands before selecting one. > And I have to say that *every* model has such issue. > Most commonly this is a sign that the AT command responses are not = formatted properly. Are you running the v250 parser by any chance? The = permissive parser is more forgiving. > So I created a workaround for this (patched ofono): > When I send AT command I start a timer that fires when no response is > received during some timeout. So if timeout is reached I send > AT+CFUN=3D1,1 > command that makes modem reset. > After that modem can be usable again. If the modem responds to AT commands, then the likely cause is something = else. Most 'real' hardware deals with true modem firmware crashes = differently. > > I was surprised that ofono doesn't have such functionality. > > So I think ofono should have some sort of mechanism to reset the modem > if it stops responding. > What do you think? > Share the AT command logs of when this happens, maybe there is a simpler = fix. Regards, -Denis --===============7047336494910838222==--