Re: Raspberry Pi 3B USB Printing Issue

From: Hans Petter Selasky <hps_at_selasky.org>
Date: Sun, 27 Mar 2022 08:04:52 UTC
On 3/27/22 07:55, Archimedes Gaviola wrote:
> On Sat, Mar 12, 2022 at 4:41 PM Hans Petter Selasky <hps@selasky.org> wrote:
> 
>> On 3/12/22 08:07, Archimedes Gaviola wrote:
>>> ugen1.5: <EPSON EPSON UB-U03II> at usbus1
>>> ulpt1 on uhub1
>>> ulpt1: <EPSON EPSON UB-U03II, class 0/0, rev 1.10/2.00, addr 5> on usbus1
>>> device_attach: ulpt1 attach returned 12
>>
>> 12 : man errno :
>>        12 ENOMEM Cannot allocate memory.
>>
>> I guess the EPSON printer you've got is not compatible with ulpt<n>
>>
>> When printing, can you make sure that the length transferred is never a
>> multiple of 64 bytes?
>>
>> Also, there might be a bug lurking in the USB host controller driver,
>> like already mentioned.
>>
> 
> 
> Hi Hans,
> 
> I just figured-out the ulpt(4) driver in my Epson printer while comparing
> with my Xprinter printer's USB device info. My Epson printer is providing
> vendor specific values of 255 in the bInterfaceClass and bInterfaceSubClass
> respectively.
> 
>        bInterfaceClass = 0x00ff  <Vendor specific>
>        bInterfaceSubClass = 0x00ff
> 
> It should be a value of 7 for bInterfaceClass and a value of 1 in
> bInterfaceSubClass.
> 
>        bInterfaceClass = 0x0007  <Printer device>
>        bInterfaceSubClass = 0x0001
> 
> So, the ulpt_attach() routine below will break upon validation for
> mismatched values in UICLASS_PRINTER and  UISUBCLASS_PRINTER.
> 
>                          } else {
>                                  alt_index++;
>                                  if ((id->bInterfaceClass ==
> UICLASS_PRINTER) &&
>                                      (id->bInterfaceSubClass ==
> UISUBCLASS_PRINTER) &&
>                                      (id->bInterfaceProtocol ==
> UIPROTO_PRINTER_BI)) {
>                                          goto found;
>                                  }
>                          }
> 
> What I did is temporarily replace these values in the USB definition. In
> this case, how should the project handle this non-compliance USB devices?
> Though I will raise this to Epson if they could provide an updated firmware.
> 
> freebsd@generic:~ % diff -Nur /usr/src/sys/dev/usb/usb.h.orig
> /usr/src/sys/dev/usb/usb.h
> --- /usr/src/sys/dev/usb/usb.h.orig     2022-03-27 02:55:01.319235000 +0800
> +++ /usr/src/sys/dev/usb/usb.h  2022-03-27 02:57:10.608518000 +0800
> @@ -459,8 +459,10 @@
>   #define        UICLASS_PHYSICAL        0x05
>   #define        UICLASS_IMAGE           0x06
>   #define        UISUBCLASS_SIC          1       /* still image class */
> -#define        UICLASS_PRINTER         0x07
> -#define        UISUBCLASS_PRINTER      1
> +/* #define     UICLASS_PRINTER         0x07 */
> +/* #define     UISUBCLASS_PRINTER      1 */
> +#define        UICLASS_PRINTER         0xff
> +#define        UISUBCLASS_PRINTER      0xff
> 
> I can print now with ulpt(4) driver but need further testing for any issues.
> 
> ugen1.5: <EPSON EPSON UB-U03II> at usbus1
> ulpt0 on uhub1
> ulpt0: <EPSON EPSON UB-U03II, class 0/0, rev 1.10/2.00, addr 5> on usbus1
> ulpt_attach: setting alternate config number: 0
> ulpt0: using bi-directional mode
> 

Hi,

I think you can just extend that piece of code to accept either value 
using a boolean OR, ||.

--HPS