[sane-devel] Problem using an Epson Perfection 610 with sane-backends 1.0.21

[Olaf Meeuwissen]

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On 2010年11月29日 16:10, Martin Krüger wrote:
> 
>> The NAK reply indicates that the ESC m command is not supported, in
>> which case the command should not have been sent in the first place (and
>> color correction disabled or emulated by the backend).
>>
>> The list of usable commands in determined by the device's command level
>> (see epson2-ops.c).  What command level do you see in the debug output?
>>  It should be somewhere near the top.
>>
> I didnt find epson2-ops.c.

backends/epson2-ops.c is definitely part of the sane-backends-1.0.21
sources.

> In the debug-Output:
> [epson2] e2_set_cmd_level: D1

The D1 (and D2) levels do not support the ESC m (and ESC M) commands.
The epson backend correctly disables these commands for D1 (and does not
know about D2).  The epson2 backend only enables ESC m, and then only
for D1 and D2 level devices.

I think the epson2 backend was misled by code in the epkowa backend.
That backend mistakenly enables the ESC m command for D1 and D2 but then
explicitly disables their getting sent for all D levels.  Some logic!
# I've been maintaining the epkowa for ages and only now I notice :-(

Note that the ESC M command is required to enable selection of the
values set via ESC m, so when that command is not enabled (which is the
case for all D level definitions in all three backends) there is no
point in trying to set color correction matrices in the first place.

The right thing to do is disable the ESC m command for all D levels in
epson2-ops.c.  Patch attached.

Hope this helps,
- -- 
Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS CORPORATION
FSF Associate Member #1962               Help support software freedom
                 http://www.fsf.org/jf?referrer=1962
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