Re: Raspberry Pi 3B USB Printing Issue

From: Archimedes Gaviola <archimedes.gaviola_at_gmail.com>
Date: Fri, 11 Mar 2022 15:36:43 UTC
On Thu, Mar 10, 2022 at 8:53 PM Hans Petter Selasky <hps@selasky.org> wrote:

> On 3/10/22 13:37, Archimedes Gaviola wrote:
> > On Thu, Mar 10, 2022 at 3:47 PM Hans Petter Selasky <hps@selasky.org>
> wrote:
> >
> >> On 3/10/22 00:24, Archimedes Gaviola wrote:
> >>> On Thu, Mar 10, 2022 at 4:14 AM Hans Petter Selasky <hps@selasky.org>
> >> wrote:
> >>>
> >>>> On 3/9/22 18:55, Archimedes Gaviola wrote:
> >>>>> Hi,
> >>>>>
> >>>>> I have an Epson printer connected to one of the USB ports of my RPi
> 3B.
> >>>> The
> >>>>> printer is detected as a ugen(4) driver and then I have a text file -
> >>>>> myfile3.txt which contains 10 lines of repeating sentences.
> >>>>>
> >>>>> freebsd@generic:~ % dmesg | grep EPSON
> >>>>> ugen1.4: <EPSON EPSON UB-U03II> at usbus1
> >>>>>
> >>>>> freebsd@generic:~ % cat myfile3.txt
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>> The quick brown fox jumps over the lazy dog.
> >>>>>
> >>>>> freebsd@generic:~ % cat myfile3.txt  > /dev/usb/1.4.1
> >>>>>
> >>>>> I print the file successfully through device file redirection with
> cat
> >>>>> command as described above. However, there were times that printing
> >>>> seemed
> >>>>> to suspend and withhold especially when my RPi 3B system got idle for
> >>>> some
> >>>>> period of time. Suspended or withhold in such a way that out of the
> 10
> >>>>> lines there were only 2-3 lines to be printed in the paper. So, the
> >> only
> >>>>> remedy I have for now is to reboot the system to be able to get back
> to
> >>>>> normal printing. I'm using the 14.0-CURRENT #0
> >> main-n253384-45c23c2608e:
> >>>>> Thu Feb 24 09:18:58 UTC 2022 and my RPi 4B does not manifest this
> >>>> behavior
> >>>>> using this same 14.0-CURRENT version. Any idea what's going on?
> >>>>>
> >>>>> I found these sysctl knobs thinking if some tweaks would help but not
> >>>> sure
> >>>>> what are the exact settings beyond these defaults.
> >>>>>
> >>>>> hw.usb.timings.port_resume_delay: 40
> >>>>> hw.usb.timings.port_powerup_delay: 300
> >>>>> hw.usb.timings.port_reset_recovery: 10
> >>>>> hw.usb.timings.port_root_reset_delay: 200
> >>>>> hw.usb.timings.port_reset_delay: 50
> >>>>>
> >>>>> (Resend this message without dmesg and sysctl outputs as files are
> >> quite
> >>>>> big, sorry I didn't notice it.)
> >>>>>
> >>>>
> >>>> Hi,
> >>>>
> >>>> Why are you not using /dev/ulpt<N> ?
> >>>>
> >>>> /dev/usb/1.4.1 is the raw BULK endpoint.
> >>>>
> >>>
> >>>
> >>> Hi Hans,
> >>>
> >>> The ulpt(4) driver isn't detected with this Epson printer. Only my
> other
> >>> printer which is an Xprinter brand is able to get detected with
> ulpt(4).
> >>>
> >>
> >> Hi,
> >>
> >> Is it correctly detected if you the VID and PID to
> >> /usr/src/sys/dev/usb/serial/ulpt.c ?
> >>
> >
> > Hi Hans,
> >
> > Not sure how to make the current ugen(4) driver into ulpt(4). Is there a
> > need to disable ugen(4) and recompile the kernel and let ulpt(4) driver
> > loaded and enabled? As far as vendor ID and product ID of this Epson
> > printer are concerned, these are  0x04b8 and  0x0200 respectively. I
> > checked it with usbconfig below. I checked also
> > /usr/src/sys/dev/usb/usbdevs file and it seems only the vendor ID is
> > present but no product ID on these particular model which is TM-U220B.
> >
> > root@generic:~ # usbconfig -u 1 -a 4 dump_device_desc
> > ugen1.4: <EPSON EPSON UB-U03II> at usbus1, cfg=0 md=HOST spd=FULL
> (12Mbps)
> > pwr=ON (10mA)
> >
> >    bLength = 0x0012
> >    bDescriptorType = 0x0001
> >    bcdUSB = 0x0110
> >    bDeviceClass = 0x0000  <Probed by interface class>
> >    bDeviceSubClass = 0x0000
> >    bDeviceProtocol = 0x0000
> >    bMaxPacketSize0 = 0x0008
> >    idVendor = 0x04b8
> >    idProduct = 0x0202
> >    bcdDevice = 0x0200
> >    iManufacturer = 0x0001  <EPSON>
> >    iProduct = 0x0002  <EPSON UB-U03II>
> >    iSerialNumber = 0x0003  <20160118193053218M03C>
> >    bNumConfigurations = 0x0001
> >
> >
> >>
> >> When you use the printer via the BULK endpoint, there might be a missing
> >> flush packet, to flush all the printed text. This happens when the
> >> payload length is a multiple of the wMaxPacketSize.
> >>
> >
> > Okay this is noted but what I found lately in usbdump are the presence of
> > ioerrors ERR=IOERROR in capturing the ugen1.4.1 device while printing
> were
> > the printed outputs are intermittent. This time I'm going to use the word
> > "intermittent" as I don't have any idea when this occurs. It just behaves
> > anytime without any warnings or notices to the system not even logs in
> the
> > dmesg. On the other hand, normal printing will prompts with ERR=0 with
> > complete outputs.
> >
> > root@generic:~ # usbdump -d ugen1.4.1 -v
> > 19:14:11.861532 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:14:12.147498 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:14:23.491555 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:14:23.777222 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:14:32.325817 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:14:32.612222 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:18:46.334624 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:18:46.620474 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:18:53.975846 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:18:54.262223 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:21:38.505907 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:21:38.792224 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:06.235833 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:06.521723 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:16.344551 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:16.630472 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:31.625887 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:31.911723 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:40.325843 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:22:40.612223 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:23:53.484761 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:23:53.514428 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,
> >   frame[0] WRITE 128 bytes
> > 19:23:57.055902 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:23:57.084227 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:00.244450 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:00.274206 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:03.974541 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:04.004203 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:24:06.975851 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:07.004209 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:09.605790 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:09.633980 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:12.385923 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:12.413760 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:15.224542 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:15.253771 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:18.174530 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:18.203756 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:21.125927 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:21.153752 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 136 bytes
> > 19:24:24.275854 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:24.303756 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:24:27.485857 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:27.772223 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:36.194633 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:36.223750 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:39.115831 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:39.143771 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:24:41.855851 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:41.883758 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:44.215882 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:44.243755 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:47.634603 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:47.663751 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:50.324493 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:50.353755 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:52.864637 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:52.893756 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:24:54.944528 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:54.973743 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:24:57.254498 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:24:57.537227 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:06.024607 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:06.053747 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:08.214550 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:08.243749 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:25:10.355858 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:10.383752 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:12.435851 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:12.463752 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:14.574555 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:14.603740 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:17.814561 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:17.844015 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:19.924529 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:19.954029 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:28.075867 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:28.104036 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> > 19:25:30.195823 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:30.224035 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:32.574567 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:32.604028 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:34.624522 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:34.654016 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 128 bytes
> > 19:25:36.895889 usbus1.4
> > SUBM-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=1264,IVAL=0
> >   frame[0] WRITE 1264 bytes
> > 19:25:36.924007 usbus1.4
> > DONE-BULK-EP=00000001,SPD=FULL,NFR=1,SLEN=0,IVAL=0,ERR=IOERROR
> >   frame[0] WRITE 144 bytes
> >
> > 86 packets captured
> > 41546 packets received by filter
> > 0 packets dropped by kernel
> >
> > What could be these ioerrors? As I am also firm that my Epson printer's
> > status is good and this only happens in RPi 3B but not RPi 4B. My RPi 4B
> > using the same printer and ugen(4) driver is very stable.
>
> Hi,
>
> IOERROR usually means an electrical error. The RPI3B will use a
> transaction translator for the FULL speed traffic, which is driven by
> software. Maybe there is a bug in the HC driver,
> "dev/usb/controller/dwc_otg.c". There are some sysctls to enable full HC
> debugging, see hw.usb.xxx.debug=17 .
>
> Is the device self-powered?
>
>
Try something like this:
>
> > diff --git a/sys/dev/usb/serial/ulpt.c b/sys/dev/usb/serial/ulpt.c
> > index c566da92437..d663800f4fc 100644
> > --- a/sys/dev/usb/serial/ulpt.c
> > +++ b/sys/dev/usb/serial/ulpt.c
> > @@ -499,6 +499,9 @@ static const STRUCT_USB_HOST_ID ulpt_devs[] = {
> >         {USB_IFACE_CLASS(UICLASS_PRINTER),
> >          USB_IFACE_SUBCLASS(UISUBCLASS_PRINTER),
> >          USB_IFACE_PROTOCOL(UIPROTO_PRINTER_1284)},
> > +
> > +       /* Epson printer */
> > +       {USB_VPI(USB_VENDOR_EPSON, USB_PRODUCT_EPSON_TMU220B, 0)},
> >  };
> >
> >  static int
> > diff --git a/sys/dev/usb/usbdevs b/sys/dev/usb/usbdevs
> > index 01c25d7c096..632b8f19610 100644
> > --- a/sys/dev/usb/usbdevs
> > +++ b/sys/dev/usb/usbdevs
> > @@ -1941,6 +1941,7 @@ product EPSON 1270                0x0120
> Perfection 1270 scanner
> >  product EPSON 2480             0x0121  Perfection 2480 scanner
> >  product EPSON 3590             0x0122  Perfection 3590 scanner
> >  product EPSON 4990             0x012a  Perfection 4990 Photo scanner
> > +product EPSON TMU220B          0x0200  TM-U220B
> >  product EPSON CRESSI_EDY       0x0521  Cressi Edy diving computer
> >  product EPSON N2ITION3         0x0522  Zeagle N2iTion3 diving computer
> >  product EPSON STYLUS_875DC     0x0601  Stylus Photo 875DC Card Reader
>
>
Hi Hans,

The patch above has no effect. My Epson printer is still obtaining the
ugen(4) driver after I apply and recompile the kernel. Anything I've missed?

Thanks,
Archimedes