[sane-devel] proper use of GT68XX_FLAG_NO_POWER_STATUS?

Nico Hoffmann oxensepp at gmx.de
Sun May 19 15:29:33 UTC 2013

On Sun, 17 Mar 2013, Stef wrote:

> On 16/03/2013 13:38, Nico Hoffmann wrote:
>>  Hi,
>>  i've have maybe a rather stupid question, but here we go:
>>  I own an older scanner plustek optic slim 1200, which uses the gt68xx
>>  backend. For years, it worked fine with sane. Since several month (at
>>  least with sane-backends 1.0.23), I can not use this scanner anymore,
>>  because it fails with following message:
>> |  # ./scanimage -x 10cm -y 10 cm > bla.img
>> |  [gt68xx] sane_open: power control failure: check power plug!
>> |  scanimage: open of device gt68xx:libusb:004:006 failed: Error during
>>  device I/O
>>  One must know: The plustek optic slim 1200 is powrered by USB
>>  only. There is no possibillity to plug in a power adapter...
>>  So I asked google and got a hint to "GT68XX_FLAG_NO_POWER_STATUS".
>>  I found it in sane-backends-1.0.23/backend/gt68xx_low.h:
>>  #define GT68XX_FLAG_NO_POWER_STATUS (1 << 7)    /*
>>  get_power_status_doesn't work */
>>  I am not familiar with the use of such flags, but for my
>>  understanding, actually this flag should be set. At least, one bit in
>>  it is set (and, despite of that, I get the power plug error).
>>  I set
>>  #define GT68XX_FLAG_NO_POWER_STATUS (0 << 7)
>>  and recompiled sane, but no change.
>>  Additionally, I erased all appearances of
>>  "GT68XX_FLAG_NO_POWER_STATUS" in gt68xx_devices.c and gt68xx_gt6816.c,
>>  and recompiled it again, but no change.
>>  So my stupid question is: How I have to change the sources to
>>  get this scanner working?
>>  kind regards,
>>  N.
>    Hello,
>    you don't need to change the meaning of the flag. You have to add it to 
> the description matching your scanner in the devices description  in 
> gt68xx_devices.c . You can find the right by the vendor/product ids at the 
> end of the file.

Thank you for your hint. I finally got it working.

In gt68xx_devices.c, struct "static GT68xx_Model
plustek_opticslim1200_model", I exchanged the last entry "0" with
"GT68XX_FLAG_NO_POWER_STATUS". This is line 1752 in v-1.0.23.

In words of diff:

   diff gt68xx_devices.c_bak gt68xx_devices.c
   <   0

After recompiling, the scanner is working now as expected.

That's all.

Of course, this small change should inserted into the sources. Can do
this someone for me? Otherwise, I would have to create a bug tracker
account only for this small issue, if I understood it correctly.



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