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i2c: recovery: require either get_sda or set_sda

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For bus recovery, we either need to bail out early if we can read SDA or
we need to send STOP after every pulse. Otherwise recovery might be
misinterpreted as an unwanted write. So, require one of those SDA
handling functions to avoid this problem.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Wolfram Sang
2018-07-10 23:42:16 +02:00
committed by Wolfram Sang
parent 08948b7593
commit ffc59c496b
2 changed files with 12 additions and 7 deletions
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7
drivers/i2c/i2c-core-base.c
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@@ -202,7 +202,8 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
/*
* If we can set SDA, we will always create STOP here to ensure
* the additional pulses will do no harm. This is achieved by
* letting SDA follow SCL half a cycle later.
* letting SDA follow SCL half a cycle later. Check the
* 'incomplete_write_byte' fault injector for details.
*/
ndelay(RECOVERY_NDELAY / 2);
if (bri->set_sda)
@@ -274,6 +275,10 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
err_str = "no {get|set}_scl() found";
goto err;
}
if (!bri->set_sda && !bri->get_sda) {
err_str = "either get_sda() or set_sda() needed";
goto err;
}
}
return;