linux-kernel - [PATCH] Input: elan_i2c - only increment wakeup count on touch

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Message-Id: <20200630005707.2181126-1-dbasehore@chromium.org>
Date:   Mon, 29 Jun 2020 17:57:07 -0700
From:   Derek Basehore <dbasehore@...omium.org>
To:     unlisted-recipients:; (no To-header on input)
Cc:     dmitry.torokhov@...il.com, dbasehore@...omium.org,
        jiada_wang@...tor.com, jeffrey.l.hugo@...il.com,
        benjamin.tissoires@...hat.com, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] Input: elan_i2c - only increment wakeup count on touch

This moves the wakeup increment for elan devices to the touch report.
This prevents the drivers from incorrectly reporting a wakeup when the
resume callback resets then device, which causes an interrupt to
occur. This also avoids error messages when these interrupts occur,
since this behavior is expected.

Signed-off-by: Derek Basehore <dbasehore@...omium.org>
---
 drivers/input/mouse/elan_i2c_core.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index cdbe6b38c73c1..6ad53a75f9807 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -49,6 +49,7 @@
 
 #define ETP_MAX_FINGERS		5
 #define ETP_FINGER_DATA_LEN	5
+#define ETP_REPORT_LEN_OFFSET	0
 #define ETP_REPORT_ID		0x5D
 #define ETP_TP_REPORT_ID	0x5E
 #define ETP_REPORT_ID_OFFSET	2
@@ -1018,6 +1019,8 @@ static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
 	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
 	bool contact_valid, hover_event;
 
+	pm_wakeup_event(&data->client->dev, 0);
+
 	hover_event = hover_info & 0x40;
 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
 		contact_valid = tp_info & (1U << (3 + i));
@@ -1041,6 +1044,8 @@ static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
 	u8 *packet = &report[ETP_REPORT_ID_OFFSET + 1];
 	int x, y;
 
+	pm_wakeup_event(&data->client->dev, 0);
+
 	if (!data->tp_input) {
 		dev_warn_once(&data->client->dev,
 			      "received a trackpoint report while no trackpoint device has been created. Please report upstream.\n");
@@ -1065,7 +1070,6 @@ static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
 static irqreturn_t elan_isr(int irq, void *dev_id)
 {
 	struct elan_tp_data *data = dev_id;
-	struct device *dev = &data->client->dev;
 	int error;
 	u8 report[ETP_MAX_REPORT_LEN];
 
@@ -1083,7 +1087,13 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
 	if (error)
 		goto out;
 
-	pm_wakeup_event(dev, 0);
+	/*
+	 * Controllers may send a full length report on power on and reset
+	 * cases. There are only meaningless bytes in these reports except for
+	 * report[ETP_REPORT_LEN_OFFSET], which is 0.
+	 */
+	if (!report[ETP_REPORT_LEN_OFFSET])
+		goto out;
 
 	switch (report[ETP_REPORT_ID_OFFSET]) {
 	case ETP_REPORT_ID:
@@ -1093,7 +1103,7 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
 		elan_report_trackpoint(data, report);
 		break;
 	default:
-		dev_err(dev, "invalid report id data (%x)\n",
+		dev_err(&data->client->dev, "invalid report id data (%x)\n",
 			report[ETP_REPORT_ID_OFFSET]);
 	}
 
-- 
2.27.0.212.ge8ba1cc988-goog