[sane-devel] CX5200 problem ...[debianbugs@saahbs.net: recompiled libsane with debugging symbols and stepped through the code...]

[Michal Sabala]

Hello Sane-devel,

I have an Epson CX5200 MFP. Upon upgrading to libsane 1.0.18 and libusb
0.1.12, I cannot use the scanner.

I traced the problem to epson.c's get_identity2_information() where it
fails due to an "incorrect" value in the return buffer. My cx5200, along
other users cx5200s, has 0xb0 (176) in buf[0] which has the most
significant bit (0x80) set.

Since this scanner worked with libsane 1.0.17 and libusb 0.1.10, and the
check for the most significant bit was always done, I suspect that
libusb now handles MFP devices differently. Attached email has a simple
patch which allows CX5200 to work without problems.

Patched libsane works correctly and with the same extents, color depths
and dpi options which were available with libsane 1.0.17 and libusb
0.1.10.

Attached is a full debug output of scanimage -L with the following env:
  SANE_DEBUG_DLL=256
  SANE_DEBUG_SANEI_USB=256
  SANE_DEBUG_EPSON=256

Please note that the first byte of the 88 byte buffer contains (0xb0)
which was rejected by get_identity2_information() without my patch.

Thanks, Michal

-- 
Michal "Saahbs" Sabala
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