On Apr 22, 2014, at 12:10 PM, Thiago Macieira <thiago.macie...@intel.com> wrote:
> Em ter 22 abr 2014, às 19:34:48, Denis Shienkov escreveu: >> 1. or keep it as is, but then bytesWritten() will be "tell lies" > > It's not lying. It's telling the user that the bytes were written from the > QIODevice to the underlying device. That's the best we can do, since now > those > bytes are no longer under our control. I fully agree with this assessment. Many platforms don’t even provide any means of notification that a physical transmit buffer is empty. They could, but they don’t. RS-485 direction switching needs to be done at the driver level, not in the userland, unless the userland implements the driver. So this is possible for user-mode USB drivers. Incidentally, my experience with user-mode drivers is much better than with kernel drivers, especially for “serial-like” devices. I think that QSerialPort should provide abstract base classes that could be reimplemented for various types of hardware. For me, the FTDI devices work much better on Linux and OS X with self-written user-mode drivers where I have full control over what’s going on. Incidentally, I have notifications of the USB transactions being finished, and of the device FIFOs emptying. I could do software DTR switching if I needed it. Using stock drivers it’s impossible. I only use it for diagnostics, though. Cheers, Kuba Ober _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
