Am 08.09.2023 um 15:53 schrieb Sascha Hauer:
> On Fri, Sep 08, 2023 at 12:16:46PM +0200, Gerald Loacker wrote:
>> The i2c bus gets disabled without sending a stop condition. This violates
>> i2c timing on the clock line. Fix this and include all related functions
>> (rk_i2c_send_start_bit, rk_i2c_send_stop_bit, rk_i2c_disable) onto the same
>> level.
>>
>> Signed-off-by: Gerald Loacker <[email protected]>
>> ---
>> drivers/i2c/busses/i2c-rockchip.c | 21 ++++++++-------------
>> 1 file changed, 8 insertions(+), 13 deletions(-)
>>
>> @@ -387,6 +376,11 @@ static int rockchip_i2c_xfer(struct i2c_adapter
>> *adapter, struct i2c_msg *msgs,
>> struct i2c_msg *msg = &msgs[i];
>>
>> dev_dbg(dev, "i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr,
>> msg->len);
>> +
>> + ret = rk_i2c_send_start_bit(i2c);
>> + if (ret)
>> + break;
>> +
>> if (msg->flags & I2C_M_RD) {
>> ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf,
>> msg->len);
>> @@ -394,6 +388,9 @@ static int rockchip_i2c_xfer(struct i2c_adapter
>> *adapter, struct i2c_msg *msgs,
>> ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf,
>> msg->len);
>> }
>> +
>> + rk_i2c_send_stop_bit(i2c);
>> +
>> if (ret) {
>> dev_dbg(dev, "i2c_write: error sending: %pe\n",
>> ERR_PTR(ret));
>> @@ -402,9 +399,7 @@ static int rockchip_i2c_xfer(struct i2c_adapter
>> *adapter, struct i2c_msg *msgs,
>> }
>> }
>>
>> - rk_i2c_send_stop_bit(i2c);
>
> I believe this is wrong. A stop bit should only be sent after the last
> message, not after all messages.
>
Your're right. This was just because the repeated start does not work
consitently in our case. I'll come up with another approach.
Gerald
> Sascha
>
