From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E454AC43441 for ; Wed, 28 Nov 2018 16:32:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7364206B6 for ; Wed, 28 Nov 2018 16:32:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="CUusFWFn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7364206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729027AbeK2Deu (ORCPT ); Wed, 28 Nov 2018 22:34:50 -0500 Received: from mail-pl1-f172.google.com ([209.85.214.172]:35332 "EHLO mail-pl1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727979AbeK2Deu (ORCPT ); Wed, 28 Nov 2018 22:34:50 -0500 Received: by mail-pl1-f172.google.com with SMTP id p8so7345465plo.2 for ; Wed, 28 Nov 2018 08:32:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:content-transfer-encoding:to:from:in-reply-to:cc :references:message-id:user-agent:subject:date; bh=RkGRvaP7pt2XjblG8B+TkNrAtFvT4aT+DbdycSXiqRY=; b=CUusFWFn10L4e8zfHw1SFyw+HriDiirTehBNME3tq+7ZDq7wAsTXoxKI9b1xycH5w6 LeNoPkC4cLX0vRXgei2i7+7Eo93mGY/5qilACkjCpCqGfGfovI+0pGmVid1/W9GsHYib b52fqWYAQk9OVDkZ9zUtnCqTt+gltKQejhFpU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:content-transfer-encoding:to:from :in-reply-to:cc:references:message-id:user-agent:subject:date; bh=RkGRvaP7pt2XjblG8B+TkNrAtFvT4aT+DbdycSXiqRY=; b=Syno9Xzt73S3ORy06itVA3EiHb3VmqTpG5J++NGMZskIevIyzU36Ixy8IzTLtGXCl5 mu6Ju/V0CVm49dVJ5kjkIsUo/1Q6S5bYuiDAsi/fFY1TQjxGHM8mq1on701qCw21CvSE MqdBQiyEpDFxaIiIftIfth2rHUczCoscn2heWRYODqOP79UnuJniTXWvE12Imnt+kKHs OBKmqxHw+ed9Lyh+iRW6qsSj+iX1KKsL93nwX3PGGsZOcP5ECbp9G7eODoFdPRuAvmS7 QQRaSE0zPUIYTPv+PpvYSXKg/fvS4hnfHNz+D32TxwZzbBCRXr1xwCdHfdsRSiAvMYwb QF3g== X-Gm-Message-State: AA+aEWZ2JaherwZ/LG2K3r/ceb1t7z8LR4pyDjstfINVe3pQXP4yS/QW dYd5+e0x9g4OWsmJ2FxePe02+g== X-Google-Smtp-Source: AFSGD/X9rjb+ImJD68vkCniDDSd7cbfZsU1ZhbZlOAYedDO6btRz9e51ER2nyzHqyOBuiv7oGb/FLQ== X-Received: by 2002:a17:902:820d:: with SMTP id x13mr38432898pln.229.1543422756542; Wed, 28 Nov 2018 08:32:36 -0800 (PST) Received: from localhost ([2620:15c:202:1:fed3:9637:a13a:6c15]) by smtp.gmail.com with ESMTPSA id b2sm12517289pfm.3.2018.11.28.08.32.35 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 28 Nov 2018 08:32:35 -0800 (PST) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable To: Ryan Case From: Stephen Boyd In-Reply-To: Cc: Greg Kroah-Hartman , Jiri Slaby , Evan Green , Doug Anderson , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org References: <20181127022536.104663-1-ryandcase@chromium.org> <154336440880.88331.11610393939844825622@swboyd.mtv.corp.google.com> <154337068886.88331.5708018437286125025@swboyd.mtv.corp.google.com> Message-ID: <154342275484.88331.11625853632580952641@swboyd.mtv.corp.google.com> User-Agent: alot/0.7 Subject: Re: [PATCH] tty: serial: qcom_geni_serial: Fix softlock Date: Wed, 28 Nov 2018 08:32:34 -0800 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Ryan Case (2018-11-27 18:37:15) > On Tue, Nov 27, 2018 at 6:04 PM Stephen Boyd wrote: > > > > Quoting Ryan Case (2018-11-27 17:24:44) > > > > > I hope underflow is impossible as well. However, if the hardware did > > > wind up in a strange state I wanted to err on the side of not throwing > > > away data and being able to resume later if things recovered. I can > > > remove the defensive checks if that's the custom, otherwise I'll > > > update the comparison logic accordingly. > > > > Well it looks like impossible code because an unsigned value can't be > > less than zero. So it's not about customs, more about dead code removal. > = > Agreed on the current dead code aspect which is why I offered the > option of updating the comparison logic, but I can just delete it if > you want. Ok, got it.