Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753375AbbGNTB0 (ORCPT ); Tue, 14 Jul 2015 15:01:26 -0400 Received: from lb1-smtp-cloud3.xs4all.net ([194.109.24.22]:49106 "EHLO lb1-smtp-cloud3.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121AbbGNTBY (ORCPT ); Tue, 14 Jul 2015 15:01:24 -0400 Message-ID: <1436900480.2679.47.camel@tiscali.nl> Subject: Re: [PATCH 1/2] isdn/gigaset: reset tty->receive_room when attaching ser_gigaset From: Paul Bolle To: Tilman Schmidt , Peter Hurley Cc: netdev@vger.kernel.org, David Miller , Hansjoerg Lipp , linux-kernel@vger.kernel.org Date: Tue, 14 Jul 2015 21:01:20 +0200 In-Reply-To: <55A450A0.4080806@imap.cc> References: <55A44662.4080706@hurleysoftware.com> <55A450A0.4080806@imap.cc> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.3 (3.16.3-2.fc22) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1484 Lines: 34 On di, 2015-07-14 at 01:58 +0200, Tilman Schmidt wrote: > Am 14.07.2015 um 01:14 schrieb Peter Hurley: > > That commit didn't cause the problem; it was a bug all along. > > Sure. That's why it is correctly fixed in the Gigaset driver. > But before that commit the bug was never actually triggered. > So that commit defines the point in the commit history from > which the fix is needed, and therefore needs to be mentioned > in order to decide which stable releases will need the fix. Yes, this seems a classic example of a bugfix that reveals another bug. So the Fixes: tag, which does sound a bit awkward, really is appropriate. For ser-gigaset about the only line discipline change that will be triggered, in practice, is from N_TTY to N_GIGASET_M101. Until commit 79901317ce80 ("n_tty: Don't flush buffer when closing ldisc") that change would set receive_room to N_TTY_BUF_SIZE (ie, 4096). This patch will set receive_room for ser-gigaset to RBUFSIZE/2 (ie, again 4096). So we're back at the pre v3.10 behavior. I'm really thankful that Tilman managed to bisect this and subsequently saw how it could be properly fixed. I hope to forward this patch in a few weeks so that it might finally be fixed in v4.3. Applied. Paul Bolle -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/