i2c: send STOP after successful bus recovery

If we managed to get a client release SDA again, send a STOP afterwards
to make sure we have a consistent state on the bus again.

Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 54cef80990a11aab4238a9968056246ec9c32b42..23f353630db32fdb25bb705334629ac86544fad5 100644 (file)
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -199,6 +199,18 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
        if (bri->get_sda && !bri->get_sda(adap))
                ret = -EBUSY;
 
+       /* If all went well, send STOP for a sane bus state. */
+       if (ret == 0 && bri->set_sda) {
+               bri->set_scl(adap, 0);
+               ndelay(RECOVERY_NDELAY / 2);
+               bri->set_sda(adap, 0);
+               ndelay(RECOVERY_NDELAY / 2);
+               bri->set_scl(adap, 1);
+               ndelay(RECOVERY_NDELAY / 2);
+               bri->set_sda(adap, 1);
+               ndelay(RECOVERY_NDELAY / 2);
+       }
+
        if (bri->unprepare_recovery)
                bri->unprepare_recovery(adap);