On Sun, Nov 1, 2009 at 7:33 AM, Frank Schaefer <schaefer.frank@xxxxxxx> wrote:
> Jon Smirl schrieb:
>> On Tue, Oct 20, 2009 at 4:00 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> I'm caught in this regression too, still broken in 2.6.31.5. I believe
>> the hardware I'm using won't work without DTR/RTS turned on. So I
>> suspect they aren't turned on by default anymore.
>>
>> I tried using picocom to force them on and I still couldn't get my
>> hardware to respond. Chip is a FT232RL.
>>
>> I'm still poking around trying to figure out how to make it work again.
>>
> Confirmed, RTS+DTR are dropped by default since 2.6.31.
>
> It makes sense to enable them by default (if flow control is disabled
> and baudrate is != B0) and this is what most other serial drivers do, too.
> I will create a patch which restores the old behavior.
>
> However, this is not really a kernel bug or regression.
> If an application needs specific settings to work properly, it should
> always set them explicitly.
> Assuming that the driver will choose the needed settings by default is
> bad application design.
App that broke for me is written in perl and looks like it is setting
RTS handshaking.
use Device::SerialPort;
$ob->handshake("rts");
Maybe something is missing in the userspace libraries that is
necessary for communicating this request into the kernel.
>
> Regards,
> Frank Schaefer
>
>
--
Jon Smirl
jonsmirl@xxxxxxxxx
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