linux-kernel - [PATCH] input: stmfts: Add #define STMFTS_RETRY

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Date:   Tue, 07 Jun 2022 07:38:20 +0000
From:   "Lin, Meng-Bo" <linmengbo0689@...tonmail.com>
To:     linux-kernel@...r.kernel.org
Cc:     dmitry.torokhov@...il.com, mcoquelin.stm32@...il.com,
        alexandre.torgue@...s.st.com, rydberg@...math.org,
        zhengyongjun3@...wei.com, linux-input@...r.kernel.org,
        linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org,
        ~postmarketos/upstreaming@...ts.sr.ht, andi.shyti@...sung.com,
        stephan@...hold.net, nikita@...n.ru
Subject: [PATCH] input: stmfts: Add #define STMFTS_RETRY_COUNT 3

Add #define STMFTS_RETRY_COUNT 3 to retry stmfts_command() 3 times.
Without it, STMFTS_SYSTEM_RESET or STMFTS_SLEEP_OUT may return -ETIMEDOUT
to failed attempt due to no event received for the completion.

Signed-off-by: Lin, Meng-Bo <linmengbo0689@...tonmail.com>
---
 drivers/input/touchscreen/stmfts.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
index c175d44c52f3..730035f5c62c 100644
--- a/drivers/input/touchscreen/stmfts.c
+++ b/drivers/input/touchscreen/stmfts.c
@@ -68,6 +68,7 @@
 #define STMFTS_DATA_MAX_SIZE	(STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
 #define STMFTS_MAX_FINGERS	10
 #define STMFTS_DEV_NAME		"stmfts"
+#define STMFTS_RETRY_COUNT	3
 
 enum stmfts_regulators {
 	STMFTS_REGULATOR_VDD,
@@ -317,19 +318,20 @@ static irqreturn_t stmfts_irq_handler(int irq, void *dev)
 
 static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
 {
-	int err;
+	int err, retry;
 
 	reinit_completion(&sdata->cmd_done);
 
-	err = i2c_smbus_write_byte(sdata->client, cmd);
-	if (err)
-		return err;
-
-	if (!wait_for_completion_timeout(&sdata->cmd_done,
-					 msecs_to_jiffies(1000)))
-		return -ETIMEDOUT;
+	for (retry = 0; retry < STMFTS_RETRY_COUNT; retry++) {
+		err = i2c_smbus_write_byte(sdata->client, cmd);
+		if (err)
+			return err;
 
-	return 0;
+		if (wait_for_completion_timeout(&sdata->cmd_done,
+						msecs_to_jiffies(1000)))
+			return 0;
+	}
+	return -ETIMEDOUT;
 }
 
 static int stmfts_input_open(struct input_dev *dev)
-- 
2.30.2