[BRLTTY] USB failures in windows

[Samuel Thibault]

Hi,

People on the NVDA list tried the mingw version I compiled, and they
also get problems with USB: usbReadEndpoint get errno == 116, i.e.
ETIMEDOUT, which is returned by libusb-win32 on ERROR_SEM_TIMEOUT or
ERROR_OPERATION_ABORTED.  Since the ETIMEDOUT macro is not available in
mingw, they get a message, I guess that Matt wasn't getting any error
message because ETIMEDOUT is defined in cygwin:

brltty.exe: USB: Product Description: Brailliant 40
brltty.exe: USB: Serial Number: 25000072
brltty.exe: USB: ept=81 dir=in xfr=blk pkt=64 ivl=0ms
brltty.exe: USB endpoint read error 116: Unknown error.
brltty.exe: braille driver initialization failed: bm -> usb:

brltty.exe: USB: Product Description: pm display
brltty.exe: USB: ept=82 dir=in xfr=blk pkt=64 ivl=0ms
brltty.exe: USB endpoint read error 116: Unknown error.
brltty.exe: braille driver initialization failed: fs -> usb:


This leads to two issues:
- shouldn't usbReadEndpoint report ETIMEDOUT at least at initialization?
- are ETIMEDOUT and EAGAIN really non-recoverable errors?

That said, maybe the problem should be reported to the libusb-win32 list
and we'd see there if for instance there's a problem with how brltty
uses libusb-win32.

Samuel