Hi Uwe, > can anybody comment on the appended patchset.
I'll try my very best ;) > After adding an empty transfer in the async example, only the first > run succeeds. After adding a case for empty transfers with the second > patch, consecutive runs of the sync example succeed. it's a bit odd that empty async transfers are not handled at the libusb level. Did you try tracing into libusb? Debug printing? I'm willing to apply this fix: >From 89d9684fd4dfde0fdc6d11f7ee957383b39aa954 Mon Sep 17 00:00:00 2001 From: Uwe Bonnes <[email protected]> Date: Wed, 18 Jul 2018 21:35:40 +0200 Subject: ftdi_write_data_submit: Handle empty transfers. --- src/ftdi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/ftdi.c b/src/ftdi.c index 52266d0..e2efc3a 100644 --- a/src/ftdi.c +++ b/src/ftdi.c @@ -1660,6 +1660,12 @@ struct ftdi_transfer_control *ftdi_write_data_submit(struct ftdi_context *ftdi,> if (!tc) return NULL; + if (!size) { + tc->completed = 1; + tc->offset = 0; + tc->transfer = 0; + return tc; + } transfer = libusb_alloc_transfer(0); if (!transfer) { > From 4da9e37309058ace7c354b7ac109c69df7678afa Mon Sep 17 00:00:00 2001 > From: Uwe Bonnes <[email protected]> > Date: Wed, 18 Jul 2018 21:35:19 +0200 > Subject: examples/async.c: Test empty write transfer. > > Running "async -b" will fail after the first run. > --- > > examples/async.c | 22 +++++++++++++++++----- > 1 file changed, 17 insertions(+), 5 deletions(-) > > diff --git a/examples/async.c b/examples/async.c > index 0589479..9143155 100644 > --- a/examples/async.c > +++ b/examples/async.c > @@ -132,7 +132,7 @@ int main(int argc, char **argv) > > struct ftdi_transfer_control *tc_write; > uint8_t data[3]; > if (do_read) { > > - tc_read = ftdi_read_data_submit(ftdi, data, DATA_TO_READ); > + tc_read = ftdi_read_data_submit(ftdi, data, DATA_TO_READ - 1); > > } > if (do_write) { > > tc_write = ftdi_write_data_submit(ftdi, ftdi_init, > sizeof(ftdi_init)); yuk, the ftdi_init variable really caught me in the example. I think we should choose a different variable name since ftdi_init() is also a function name in libftdi. Any explanation why "DATA_READ" was changed to "DATA_READ -1"? Cheers, Thomas -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
