summaryrefslogtreecommitdiffstats
path: root/arm64-qcom-i2c-geni-Disable-DMA-processing-on-the-Lenovo-Yoga-C630.patch
blob: a7f7c8f20675aeda623fe59c29976784967c40de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
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 <lee.jones@linaro.org>
X-Patchwork-Id: 11133827
Return-Path: <SRS0=OmJI=XA=vger.kernel.org=linux-arm-msm-owner@kernel.org>
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 <patchwork-linux-arm-msm@patchwork.kernel.org>;
 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 <patchwork-linux-arm-msm@patchwork.kernel.org>;
 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
        <rfc822;patchwork-linux-arm-msm@patchwork.kernel.org>);
        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
        <rfc822;linux-arm-msm@vger.kernel.org>);
        Thu, 5 Sep 2019 15:24:18 -0400
Received: by mail-wr1-f49.google.com with SMTP id y19so4081592wrd.3
        for <linux-arm-msm@vger.kernel.org>;
 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 <lee.jones@linaro.org>
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 <lee.jones@linaro.org>
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: <linux-arm-msm.vger.kernel.org>
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 <lee.jones@linaro.org>
---
 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