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USB low-full-high speed peripherals Forum Discussions

vpac
Level 3
Level 3
10 sign-ins 5 replies posted 5 questions asked

i develope a firmware for dvb dongle using an fx2 board.

On a linux PC:

when i connect to PC USB and firmware is downloaded, strange things happen.

on the linux PC terminal  i get strange character input at random every once in a while.

Also screen resolution changes once in a while (due to strange key input).

The firmware is not functioning as it should.

On a linux LAPTOP:

plugin the dongle into my laptop, after firmware load, kernel panic.

On a raspberry pi:

it works.

This is so strange.

the firmware is processing a lot of "vendor-commands" through EP0. ?!

i am out of ideas....

 

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1 Solution
vpac
Level 3
Level 3
10 sign-ins 5 replies posted 5 questions asked

OK, found it.

The linux DVB driver assumes an IR-remote receiver inside dvb-tuner device and creates an input device which acts as a keyboard-input (for some reason). So IR-codes arrive into your terminal window.

+++ DVB Tuner, ir-receiver inside dvb-usb not working, it sends spurious keypresses:
solution:
-> create file /etc/modprobe.d/dvb-usb.conf, containing:     options dvb-usb disable_rc_polling=1
then on probe, driver does not load ir support.

View solution in original post

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3 Replies
MallikaK_22
Moderator
Moderator
Moderator
250 solutions authored 500 replies posted 250 replies posted

Hi,

>> Is the failure on a Linux laptop happening every time or intermittently?

>> Did you check on another host?

>> Can you share the USB logs?

 

 

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vpac
Level 3
Level 3
10 sign-ins 5 replies posted 5 questions asked

yeah this is mysterious 😉

i guess it is related to my firmware, or ? vid/pid combination: its: 04b4:2104, which is DVBworld 2104 HD device,

but mine is custom hardware, same tuner.

So it maybe that linux, when recoqnizing that vid/pid trys to do something, it shouldnt.

as described above, i tryd it on 3 linux machines, only the raspberry worked fine.

just wonder if anyone has ever experienced these strange "noise" coming rom USB going to keyboard.

will check for USBMON to elaborate further.

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vpac
Level 3
Level 3
10 sign-ins 5 replies posted 5 questions asked

OK, found it.

The linux DVB driver assumes an IR-remote receiver inside dvb-tuner device and creates an input device which acts as a keyboard-input (for some reason). So IR-codes arrive into your terminal window.

+++ DVB Tuner, ir-receiver inside dvb-usb not working, it sends spurious keypresses:
solution:
-> create file /etc/modprobe.d/dvb-usb.conf, containing:     options dvb-usb disable_rc_polling=1
then on probe, driver does not load ir support.

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