Some adapters need to be prepared/unprepared before bitbanging the bus.
Do this for the initial STOP, too.

Signed-off-by: Wolfram Sang <wsa+rene...@sang-engineering.com>
---

Ok, another idea to fix the regression. I'm not 100% sure if the placement is
perfect, but it should serve well enough as a proof of concept to see if this
is the actual issue. It looks promising, though.

 drivers/i2c/algos/i2c-algo-bit.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 4a34f311e1ff..fab4437ecbb5 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -648,10 +648,19 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap,
                adap->quirks = &i2c_bit_quirk_no_clk_stretch;
 
        /* Bring bus to a known state. Looks like STOP if bus is not free yet */
+       if (bit_adap->pre_xfer) {
+               ret = bit_adap->pre_xfer(adap);
+               if (ret < 0)
+                       return ret;
+       }
+
        setscl(bit_adap, 1);
        udelay(bit_adap->udelay);
        setsda(bit_adap, 1);
 
+       if (bit_adap->post_xfer)
+               bit_adap->post_xfer(adap);
+
        ret = add_adapter(adap);
        if (ret < 0)
                return ret;
-- 
2.11.0

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