From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+IEBqSXk7XNANtocgDLlOXjeWhEHnFgftaPfo6R8K/Kln2l1iIGsO22PDcL7hYPfIsRPO1 ARC-Seal: i=1; a=rsa-sha256; t=1523178181; cv=none; d=google.com; s=arc-20160816; b=A81ULH6W10HfyfwYR0XCjVRjzYe/Zz2Cq1wms+FzO1hhLJfLCibqH6eyS2ixj6BTks KNGTfLehEYLFU4g4csevK+0YISqXWvxQQeS7H20XSKQDdmyA51nHRQtwkhd7SpNircJX 8i1wxwZ7tos1qU2tWgztTivmcyuqDD1ucxoQQzEe0L6yp9ofT3h+xZwsn8Elt9/gna5Q TAh9D+cvnGe7f6jzUwcl8FVVVo1dzVvQvfgQh9d5tjm6by+nUUu4mB3+vZ6aNb8cuI0H 5Vc54W6/Xig6aulpPZUOiDPpaQdAJ2a5vmiGDd9DNuK3kuxqlZHh++iA/lT5diQ9zIGW 8ATA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=8DWZ5fU4+tCXMeUlr2cNXxYMtLyL03tWmMgcdNI2tl0=; b=pi430o3LmXFv+lPhOpgDa1QgurTKbvDcRL7Bgy71aPULGgKjhFTcM++sKRLU/bDcfd OJuS50hy5Ynz4m7BpCFIjNcuZf170DxV/e247EIkB8xRGYP02fWhYgyiod9fhY+mLlHf Cpo+jxWIajJQa01V80LcO5POFFFkhNDn8ckiS8EB1RGtC2WCyyGCTItNL+czkbQFkyqG ni2PKM4JZ/8cSQtNkaiDoJEv9iHoE1AY4mYU0u6dtSoyLC/sEyanOiY6DEhj/6AjV1gp +3w3/i+Nc+BH5eva1YUpQr7Qxv0qMO1UsIAS5DqOF6e+PPa+l9B/+RuAeIr6AURD/3GJ wm2Q== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 195.113.26.193 is neither permitted nor denied by best guess record for domain of pavel@ucw.cz) smtp.mailfrom=pavel@ucw.cz Authentication-Results: mx.google.com; spf=neutral (google.com: 195.113.26.193 is neither permitted nor denied by best guess record for domain of pavel@ucw.cz) smtp.mailfrom=pavel@ucw.cz Date: Sun, 8 Apr 2018 11:02:59 +0200 From: Pavel Machek To: Tony Lindgren Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Alan Cox , Dan Williams , Jiri Prchal , Jiri Slaby , Marcel Partap , Merlijn Wajer , Michael Nazzareno Trimarchi , Michael Scott , Peter Hurley , Russ Gorby , Sascha Hauer , Sebastian Reichel Subject: Re: [PATCH 1/2] tty: n_gsm: Fix long delays with control frame timeouts in ADM mode Message-ID: <20180408090259.GA8185@amd> References: <20180407171951.122759-1-tony@atomide.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="u3/rZRmxL6MmkK24" Content-Disposition: inline In-Reply-To: <20180407171951.122759-1-tony@atomide.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597108755036082132?= X-GMAIL-MSGID: =?utf-8?q?1597168084477613030?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: --u3/rZRmxL6MmkK24 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Commit ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for > control dlci") added support for DLCI to stay in Asynchronous Disconnected > Mode (ADM). But we still get long delays waiting for commands to other > DLCI to complete: >=20 > --> 5) C: SABM(P) > Q> 0) C: UIH(F) > Q> 0) C: UIH(F) > Q> 0) C: UIH(F) > ... >=20 > This happens because gsm_control_send() sets cretries timer to T2 that is > by default set to 34. This will cause resend for T2 times for the control > frame. In ADM mode, we will never get a response so the control frame, so > retries are just delaying all the commands. >=20 > Let's fix the issue by setting DLCI_MODE_ADM flag after detecting the ADM > mode for the control DLCI. Then we can use that in gsm_control_send() to > set retries to 1. This means the control frame will be sent once allowing > the other end at an opportunity to switch from ADM to ABM mode. >=20 > Note that retries will be decremented in gsm_control_retransmit() so > we don't want to set it to 0 here. Thanks! I guess I'd like to test this on Droid4; there are fso-gsm0710muxd and gsm0710muxd packages in Debian, but I assume those do multiplexing in userspace and thus are not suitable? Do you have a tool to use and a script? Thanks and best regards, Pavel =09 --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --u3/rZRmxL6MmkK24 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlrJ2sMACgkQMOfwapXb+vLBzgCgpiL9rpEz5ljgj/eJaQiuL2V9 n1wAnA1caA+FYvLNcMedg6SMolYx1pUe =Mwad -----END PGP SIGNATURE----- --u3/rZRmxL6MmkK24--