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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 EB132C352AA for ; Tue, 1 Oct 2019 16:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9ED021783 for ; Tue, 1 Oct 2019 16:55:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948937; bh=z6WyRdHEuXM4BX+2/G9Bv1TDJ64UqpMMW83Y8th40I4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0+3ZCQ4VGDZhRyn9UL1sYNWXl50lNJiSPUY2D8yWFNeVefnuU1xxI3fSiOVjygNtd j6xoA6rWogQ/OGH6M8yxZc8ZX4kyOcfNesAWi9wFtqHbFWYUJFBc5j2I19rzOaPLg3 Vgjx1sR2/Xg0e0jFHXo9BHWunqPqG1KWbxp7HjLA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731174AbfJAQzZ (ORCPT ); Tue, 1 Oct 2019 12:55:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:54740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732158AbfJAQmp (ORCPT ); Tue, 1 Oct 2019 12:42:45 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2517A21920; Tue, 1 Oct 2019 16:42:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948165; bh=z6WyRdHEuXM4BX+2/G9Bv1TDJ64UqpMMW83Y8th40I4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mbBqqh8YNcTRXxoNDYx+qbsvXVi/noLyRvycl4EDUbKusrR3VxQdqNJMtoUIaaj9l Mgunod3pGGM/O5wcUjp4Y2S5oONSbvmDFHQmxhpD6oZwGNluL4fJBiFKlef4hrXcl/ FGIiGMPT+lhjlkkDXvRu/bLaqwFTrK/EyPWNbS10= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Lee Jones , Bjorn Andersson , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 51/63] i2c: qcom-geni: Disable DMA processing on the Lenovo Yoga C630 Date: Tue, 1 Oct 2019 12:41:13 -0400 Message-Id: <20191001164125.15398-51-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164125.15398-1-sashal@kernel.org> References: <20191001164125.15398-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Lee Jones [ Upstream commit 127068abe85bf3dee50df51cb039a5a987a4a666 ] 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 Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- 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 db075bc0d9525..715ddc5d0eac9 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -354,11 +354,13 @@ 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 @@ -393,11 +395,13 @@ 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 -- 2.20.1