Re: [PATCHv3 02/10] serdev: add serdev_device_wait_until_sent

[Rob Herring]

On Sat, Apr 8, 2017 at 11:57 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Mar 28, 2017 at 05:59:31PM +0200, Sebastian Reichel wrote:
>> Add method, which waits until the transmission buffer has been sent.
>> Note, that the change in ttyport_write_wakeup is related, since
>> tty_wait_until_sent will hang without that change.
>>
>> Acked-by: Rob Herring <robh@xxxxxxxxxx>
>> Acked-by: Pavel Machek <pavel@xxxxxx>
>> Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
>> ---
>> Changes since PATCHv2:
>>  * Avoid goto in ttyport_write_wakeup
>> ---
>>  drivers/tty/serdev/core.c           | 11 +++++++++++
>>  drivers/tty/serdev/serdev-ttyport.c | 18 ++++++++++++++----
>>  include/linux/serdev.h              |  3 +++
>>  3 files changed, 28 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
>> index f4c6c90add78..a63b74031e22 100644
>> --- a/drivers/tty/serdev/core.c
>> +++ b/drivers/tty/serdev/core.c
>> @@ -173,6 +173,17 @@ void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
>>  }
>>  EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
>>
>> +void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
>> +{
>> +     struct serdev_controller *ctrl = serdev->ctrl;
>> +
>> +     if (!ctrl || !ctrl->ops->wait_until_sent)
>> +             return;
>> +
>> +     ctrl->ops->wait_until_sent(ctrl, timeout);
>> +}
>> +EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
>
> Is this still needed now that we have serdev_device_write() with an
> unlimited timeout available?

Yes, because only this waits until the data is on the wire.

Rob