From patchwork Thu Sep 5 19:24:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 11133827 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DDFD514ED for ; Thu, 5 Sep 2019 19:24:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D540020870 for ; Thu, 5 Sep 2019 19:24:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="j/6kUy9p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727540AbfIETYS (ORCPT ); Thu, 5 Sep 2019 15:24:18 -0400 Received: from mail-wr1-f49.google.com ([209.85.221.49]:36821 "EHLO mail-wr1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726008AbfIETYS (ORCPT ); Thu, 5 Sep 2019 15:24:18 -0400 Received: by mail-wr1-f49.google.com with SMTP id y19so4081592wrd.3 for ; Thu, 05 Sep 2019 12:24:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=19vbMBbLeKgWt8VsEseKuJu+9+rmeS/Lh0ZhXOFWQYc=; b=j/6kUy9psCaV+YLvz8j0kAZ3/WrmOU3xyh5rDOj0TwK0TnwjLtaLil9Q+C9KpFvvVG h4R8p4cZFB0U4b/PAfc9Xt4p4xJNkAIpTzL4QRjM+nkXdDcYyiwUGkr9BRJnJmO0lyZB zmylqwjRd1oOrTQ1tPvwqUV3OUR5u6WA+rDyhn+A516vskkns0bEICMG787HdDEwjigd +3SR4L9u7swSDpNhqxtfPsn9UFP36sehUfgx32xUcjUhX3ls4RtX+6HCZU+rkeQuILt5 0qlmqliIuKXWkQe+ii/gtrK+ulFQ7lEl76YfDJyqXVo4Z357rIhVFAz+mooVn5qpscmU E+xA== 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; bh=19vbMBbLeKgWt8VsEseKuJu+9+rmeS/Lh0ZhXOFWQYc=; b=QjFuCunKeBkoabY9fIsWTo3krapsS69k52eNtOIeLBaCd7M1lvCmItn41DcbJ5ykqT RQ0rnlNq35x9QvKNumPai3fMZp9AWt3KpJpxbpEokltyLbkGUqRWaeYTrOtuV9P9nRmT Yj72UBVzYj4d/G+FGq8EBesWjRyEFC51+RekvPlbRZ/h1fVW7/XAy5cO1ywnHrtNe8pQ 7gYQJ3Xh1Y09qkiO0i8iru5PSMTK3U+vPSLWVdFOeqMh+Beins6I9mbKf+UX+xa8ECK3 mEFjYxY57YVx+SpaKrmBwEmu9YXLgXqEif1OH1FHFiKZVQ4ABPp19D4+5JOXEV1tCwUS B6Qw== X-Gm-Message-State: APjAAAUM7yEkrkGZ+mbleFtCMQGsXfLQSXt2Bd+K6leuP2oAs8Vj1j9k 4bsoJvF042q/z9+6bnLlGShjoA== X-Google-Smtp-Source: APXvYqyThx0kWliMdrjc7dedZ/+AhabFi7TIc04exnxhWAEkAOh7foRP8Cz8ZjjhxGJCvUyUPA4lFg== X-Received: by 2002:adf:ea0c:: with SMTP id q12mr4172788wrm.172.1567711455933; Thu, 05 Sep 2019 12:24:15 -0700 (PDT) Received: from localhost.localdomain ([95.147.198.36]) by smtp.gmail.com with ESMTPSA id q24sm7942378wmc.3.2019.09.05.12.24.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Sep 2019 12:24:14 -0700 (PDT) From: Lee Jones To: alokc@codeaurora.org, agross@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, bjorn.andersson@linaro.org, vkoul@kernel.org, wsa@the-dreams.de Cc: linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, Lee Jones Subject: [RESEND v3 1/1] i2c: qcom-geni: Disable DMA processing on the Lenovo Yoga C630 Date: Thu, 5 Sep 2019 20:24:12 +0100 Message-Id: <20190905192412.23116-1-lee.jones@linaro.org> X-Mailer: git-send-email 2.17.1 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org We have a production-level laptop (Lenovo Yoga C630) which is exhibiting a rather horrific bug. When I2C HID devices are being scanned for at boot-time the QCom Geni based I2C (Serial Engine) attempts to use DMA. When it does, the laptop reboots and the user never sees the OS. Attempts are being made to debug the reason for the spontaneous reboot. No luck so far, hence the requirement for this hot-fix. This workaround will be removed once we have a viable fix. Signed-off-by: Lee Jones Tested-by: Bjorn Andersson --- drivers/i2c/busses/i2c-qcom-geni.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index a89bfce5388e..17abf60c94ae 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -355,11 +355,13 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, { dma_addr_t rx_dma; unsigned long time_left; - void *dma_buf; + void *dma_buf = NULL; struct geni_se *se = &gi2c->se; size_t len = msg->len; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (!of_machine_is_compatible("lenovo,yoga-c630")) + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else @@ -394,11 +396,13 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, { dma_addr_t tx_dma; unsigned long time_left; - void *dma_buf; + void *dma_buf = NULL; struct geni_se *se = &gi2c->se; size_t len = msg->len; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (!of_machine_is_compatible("lenovo,yoga-c630")) + dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else