Messages in this thread | | | Date | Sat, 5 May 2007 12:19:51 +0200 | From | "Antonino Ingargiola" <> | Subject | Re: [SOLVED] Serial buffer corruption [was Re: FTDI usb-serial possible bug] |
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On 5/5/07, Antonino Ingargiola <tritemio@gmail.com> wrote: > On 5/4/07, Paul Fulghum <paulkf@microgate.com> wrote: > > Antonino: > > > > Can you try two tests (with my patch applied): > > > > 1. comment out the tty_flush_buffer() call in tty_ldisc_flush() and test > > > > 2. uncomment (reenable) the above call and comment out the > > tty_flush_buffer() call in tty_ioctl() and test > > I assume you meant tty_buffer_flush(). I've built kernel 1). In kernel > 2), do you mean: > > /*if (ld->ioctl) > tty_buffer_flush(tty);*/ > tty_ldisc_deref(ld); > > right? This is what I'm building... I'll report these new tests soon.
Ok test done.
With kernel 1. the behavior is the same as with your plain second patch only (flush input works but I cannot read anymore from the serial that was flushed without closing and reopening the port). See previous mail for the details of the test.
With kernel 2 the behavior is the same as mainline (multiple flushes are needed to completely empty the buffers). And I _can_ read further chars from the serial line after the flush. Here it is the ipython session that document the test with kernel 2:
In [1]: import serial
In [2]: s0 = serial.Serial(0, timeout=1)
In [3]: s1 = serial.Serial(1, timeout=1)
In [4]: s0.write('test\n')
In [5]: s1.inWaiting() Out[5]: 5L
In [6]: s1.readline() Out[6]: 'test\n'
In [7]: for i in xrange(1000): ...: s0.write(str(i).zfill(8)+'\n') ...:
In [8]: s1.inWaiting() Out[8]: 4095L
In [9]: s1.flushInput()
In [10]: s1.inWaiting() Out[10]: 4095L # NOTE the buffer is still full!
In [11]: s1.flushInput()
In [12]: s1.inWaiting() Out[12]: 810L # The buffer beginning to be drained
In [13]: s1.flushInput()
In [14]: s1.inWaiting() Out[14]: 0L # Now the buffer is empty
In [15]: s0.write('test\n') # An reading further chars works
In [16]: s1.inWaiting() Out[16]: 5L
In [17]: s1.readline() Out[17]: 'test\n'
Regards,
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