[cups] USB quirk rules

[Michael Weghorn]

Hi Michael,

thank you for your reply which gives more clarity. We will possibly
address that topic with our supplier again.

On 2017-09-05 23:15, Michael Sweet wrote:
> Michael,
> 
> If every printer (or even most printers) needed the same quirks, then there might be something to your supplier's claim that the problem lies in CUPS' implementation.  However, that is not the case...
> 
> Unfortunately, printer manufacturers have been shipping broken USB implementations for years, and every OS vendor has had to implement some sort of "quirks" mechanism for their USB printer support.
> 
> 
> 
> 
>> On Sep 1, 2017, at 8:11 AM, Michael Weghorn <m.weghorn at posteo.de> wrote:
>>
>> Hi,
>>
>> by adding printers to the USB backend quirks file in CUPS, known issues when printing with CUPS on various USB printers can be worked around.
>>
>> So far I was assuming (without actually knowing) that the underlying problems were bugs in the respective printer hardware (e.g. their firmware).
>>
>> We recently received a new printer model where printing without adding a quirk rule had issues (and the issue was gone after adding a respective USB quirk rule). When addressing the issue to our supplier, we got got as a reply that the wrong behaviour was due to a wrong CUPS handling of USB printers and we should do the following to solve the issue:
>>
>>    lpadmin -p <printername> -R usb-unidir-default
>>    lpadmin -p <printername> -o usb-no-reattach-default=true
>>
>> This is basically what the USB quirk file does "automatically".
>>
>> While adding a respective rule for a specific model is OK in a single case, I think it would be nice to have the underlying issue addressed to avoid that more or less the same problem reoccurs when a new model is introduced.
>>
>> Is it possible to get more information on the underlying cause why such workarounds are needed and where a "proper" solution would have to be implemented (if possible at all)?
>>
>> Regards,
>> Michael
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> 
> _________________________________________________________
> Michael Sweet, Senior Printing System Engineer
> 
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