Re: Raspberry Pi 3B USB Printing Issue

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
>


Hi Hans,


>
> 12 : man errno :
>       12 ENOMEM Cannot allocate memory.
>
> I guess the EPSON printer you've got is not compatible with ulpt<n>
>

Oh I see, just tried with my RPi 4B and it has the same issue with returned
12 on ENOMEM. Previously with OpenBSD it was only detected as well with the
ugen(4) driver not ulpt(4) so most likely not compatible. I will check the
manual for any settings relevant to this.


>
> When printing, can you make sure that the length transferred is never a
> multiple of 64 bytes?
>

Okay let me double check with usbdump again as these are only plain text
characters being printed with no other formats involved.


>
> Also, there might be a bug lurking in the USB host controller driver,
> like already mentioned.
>

Okay noted again, so there's a need to check and review the code of the DWC
OTG host controller driver. So this is just specific to RPi 3B. I'll
proceed on enabling the debugging settings and observed.

Thanks,
Archimedes