linux-kernel - [PATCH v2] Input: i8042 - fix the selftest retry logic

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Date:   Tue, 10 Mar 2020 11:36:40 +0800
From:   You-Sheng Yang <vicamo@...il.com>
To:     vicamo@...il.com
Cc:     acelan.kao@...onical.com, allison@...utok.net,
        dmitry.torokhov@...il.com, info@...ux.net,
        linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        rafael.j.wysocki@...el.com, swboyd@...omium.org,
        tglx@...utronix.de, You-Sheng Yang <vicamo.yang@...onical.com>
Subject: [PATCH v2] Input: i8042 - fix the selftest retry logic

From: You-Sheng Yang <vicamo.yang@...onical.com>

It returns -NODEV at the first selftest timeout, so the retry logic
doesn't work. Move the return outside of the while loop to make it real
retry 5 times before returns -ENODEV.

BTW, the origin loop will retry 6 times, also fix this.

Signed-off-by: You-Sheng Yang <vicamo.yang@...onical.com>
---
 drivers/input/serio/i8042.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 20ff2bed3917..e8f2004071d4 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -937,25 +937,28 @@ static int i8042_controller_selftest(void)
 {
 	unsigned char param;
 	int i = 0;
+	int ret;
 
 	/*
 	 * We try this 5 times; on some really fragile systems this does not
 	 * take the first time...
 	 */
-	do {
-
-		if (i8042_command(&param, I8042_CMD_CTL_TEST)) {
-			pr_err("i8042 controller selftest timeout\n");
-			return -ENODEV;
-		}
+	while (i++ < 5) {
 
-		if (param == I8042_RET_CTL_TEST)
+		ret = i8042_command(&param, I8042_CMD_CTL_TEST);
+		if (ret)
+			pr_err("i8042 controller selftest timeout (%d/5)\n", i);
+		else if (param == I8042_RET_CTL_TEST)
 			return 0;
+		else
+			dbg("i8042 controller selftest: %#x != %#x\n",
+			    param, I8042_RET_CTL_TEST);
 
-		dbg("i8042 controller selftest: %#x != %#x\n",
-		    param, I8042_RET_CTL_TEST);
 		msleep(50);
-	} while (i++ < 5);
+	}
+
+	if (ret)
+		return -ENODEV;
 
 #ifdef CONFIG_X86
 	/*
-- 
2.25.0