From patchwork Tue Oct 13 21:25:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 269626 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=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=no 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 E7DEEC4363A for ; Wed, 14 Oct 2020 09:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CE56206F4 for ; Wed, 14 Oct 2020 09:30:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="EQTxzxUu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727449AbgJNJaa (ORCPT ); Wed, 14 Oct 2020 05:30:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729685AbgJNJTi (ORCPT ); Wed, 14 Oct 2020 05:19:38 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A9EBC0613D7 for ; Tue, 13 Oct 2020 14:26:22 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id x16so532334pgj.3 for ; Tue, 13 Oct 2020 14:26:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OoAVR9AHVrF5AmfQOiW6xvU4LK/5cY35UObNq6NT9XE=; b=EQTxzxUuIKTcB+XY70IZK53ZA9IwEFA63ysUwVxyS6E2XHi8jvNKV1KDaWxPQOMZwa DpWi781oIYquJ8RoAVv9BkQ8pmtZdjPU+u2OYk/cOqkvKpFXOplZdLqRCARtqWwa6WM8 M7r+0Nwo0XKiYriJXGI2rMUfGAmFqR3fW0Wl0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OoAVR9AHVrF5AmfQOiW6xvU4LK/5cY35UObNq6NT9XE=; b=oxbVV2rSL+IfTziIm2BvyEfzP1IF6WG4OhzLbd9T8rat1s+LzvPoiPG/Yy903ACoRf ltb/5y449dxi289842j1Z2x/NEGHR2a5mAZK4cbbhWjRtId9YdCr49Dt2W2Fs2Twq6qX YLpuZTBsFwaOmlyS6+ULgDI1C2E2DpsYqyfbi27vNAdvnLSakS6FQjFB2xFtIJr49RYr ZwmPkbZgyj7qazM9CjlHljnshinzdPo2AH0Cu6FFjjsqitBUC2TGW65iAFSQoP01W9cZ X/P4c8zk5ekmsx+vz95BJr5+Iz6T8CAsoPLEeNJmTyijLNx74c1lxTXqXgbV2A+HZSQg lMNg== X-Gm-Message-State: AOAM530GXjcLkTAlXYV31rrsKgXHV2FJmc7v/N+X3Mvk7ebYTA17Wk4C VkFgrS/trwkAKHsOrqLhtM3gqg== X-Google-Smtp-Source: ABdhPJxjpE+t6tSF6IoGOjD0t+fTHO4qbXOhNCwIJqg8rHVYSn4dWpiqWHiGitjlRTuGvKhaxa/vBA== X-Received: by 2002:a63:fe49:: with SMTP id x9mr1177056pgj.192.1602624381982; Tue, 13 Oct 2020 14:26:21 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:42b0:34ff:fe3d:58e6]) by smtp.gmail.com with ESMTPSA id b15sm167713pju.16.2020.10.13.14.26.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Oct 2020 14:26:21 -0700 (PDT) From: Douglas Anderson To: Bjorn Andersson , Wolfram Sang , Akash Asthana Cc: linux-i2c@vger.kernel.org, Roja Rani Yarubandi , Stephen Boyd , Dmitry Baryshkov , linux-arm-msm@vger.kernel.org, Douglas Anderson , Andy Gross , Girish Mahadevan , Karthikeyan Ramasubramanian , Mukesh Kumar Savaliya , Sagar Dharia , linux-kernel@vger.kernel.org Subject: [PATCH v2 0/3] i2c: i2c-qcom-geni: More properly fix the DMA race Date: Tue, 13 Oct 2020 14:25:27 -0700 Message-Id: <20201013212531.428538-1-dianders@chromium.org> X-Mailer: git-send-email 2.28.0.1011.ga647a8990f-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Previously I landed commit 02b9aec59243 ("i2c: i2c-qcom-geni: Fix DMA transfer race") to fix a race we were seeing. While that most definitely fixed the race we were seeing, it looks like it causes problems in the TX path, which we didn't stress test until we started trying to update firmware on devices. Let's revert that patch and try another way: fix the original problem by disabling the interrupts that aren't relevant to DMA transfers. Now we can stress both TX and RX cases and see no problems. I also can't find any place to put an msleep() that causes problems anymore. Since this problem only affects i2c, I'm hoping for an Ack from Bjorn and then all these patches can go through the i2c tree. However, if maintainers want to work a different way out to land that's OK too. NOTE: the 3rd patch in the series could certianly be squashed with patch #1 or I could re-order / rejigger. To me it seemed like a good idea to first fix the probelm (and make the two functions as much of an inverse as possible) and later try to clean things up. Yell if you want something different. Changes in v2: - Consistently use "val_old" to keep track of old value. - Add comments about why UART is special. Douglas Anderson (3): soc: qcom: geni: More properly switch to DMA mode Revert "i2c: i2c-qcom-geni: Fix DMA transfer race" soc: qcom: geni: Optimize/comment select fifo/dma mode drivers/i2c/busses/i2c-qcom-geni.c | 6 ++-- drivers/soc/qcom/qcom-geni-se.c | 55 ++++++++++++++++++++++-------- 2 files changed, 43 insertions(+), 18 deletions(-) Reviewed-by: Stephen Boyd