linux-kernel - [PATCH 1/3] i2c: at91: move i2c_recover_bus() outside of at91_do_twi

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Message-ID: <20210727111554.1338832-2-codrin.ciubotariu@microchip.com>
Date:   Tue, 27 Jul 2021 14:15:52 +0300
From:   Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>
To:     <linux-i2c@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
CC:     <nicolas.ferre@...rochip.com>, <alexandre.belloni@...tlin.com>,
        <ludovic.desroches@...rochip.com>, <andrew@...people.com>,
        <mhoffman@...htlink.com>, <khali@...ux-fr.org>, <wsa@...nel.org>,
        "Codrin Ciubotariu" <codrin.ciubotariu@...rochip.com>
Subject: [PATCH 1/3] i2c: at91: move i2c_recover_bus() outside of at91_do_twi_transfer()

This patch doesn't add a functional change, it just separates the recovery
from the transfer itself.

Fixes: d3d3fdcc4c90 ("i2c: at91: implement i2c bus recovery")
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>
---
 drivers/i2c/busses/i2c-at91-master.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index 1cceb6866689..0352dc09d697 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -639,13 +639,6 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 			       AT91_TWI_THRCLR | AT91_TWI_LOCKCLR);
 	}
 
-	/*
-	 * some faulty I2C slave devices might hold SDA down;
-	 * we can send a bus clear command, hoping that the pins will be
-	 * released
-	 */
-	i2c_recover_bus(&dev->adapter);
-
 	return ret;
 }
 
@@ -705,7 +698,17 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 
 	ret = at91_do_twi_transfer(dev);
 
-	ret = (ret < 0) ? ret : num;
+	if (ret < 0) {
+		/*
+		 * some faulty I2C slave devices might hold SDA down;
+		 * we can send a bus clear command, hoping that the pins will be
+		 * released
+		 */
+		i2c_recover_bus(&dev->adapter);
+	} else {
+		ret = num;
+	}
+
 out:
 	pm_runtime_mark_last_busy(dev->dev);
 	pm_runtime_put_autosuspend(dev->dev);
-- 
2.30.2