topic Re: USB display with displaylink issue in i.MX Processors

USB display with displaylink issue

wangvictor — Mon, 26 Feb 2018 05:48:10 GMT

Hi All,

I'm using Yocto to build my image and using Ubuntu 14.04 and i.MX6 sabreSD for my OS system and CPU.

Now I'm trying to display my monitor via USB by using the ID which is displaylink DL_115.

In my kernel side I had open the config FB_UDL, I see if said is for displaylink USB interface.

However when I build in my machine and plug the USB on I can just see the green screen on my monitor.(Please see the attachment picture)

Did I miss anything here?

Thanks in Advanced!

Re: USB display with displaylink issue

igorpadykov — Mon, 26 Feb 2018 07:56:28 GMT

Hi victor

what is lcd full name, for example one can look on

GitHub - harbaum/LCD2USB: Cheap and simple USB to HD44780 text LCD interface

seems such kind of lcd is not supported in nxp bsps, so

one will have to develop appropriate driver for its usage.

Just for reference attached Linux Manual with description of

supported drivers.

Best regards
igor
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Re: USB display with displaylink issue

wangvictor — Mon, 26 Feb 2018 09:28:49 GMT

Sorry for the wrong typing.

I mean IC I use to convert USB to VGA is DL_115 which is develop from DisplayLink.

And for the source driver in Yocto i.MX6 sabreSD, I do see the driver that is for displaylink.

Re: USB display with displaylink issue

igorpadykov — Mon, 26 Feb 2018 10:25:41 GMT

one can look on

Linux and Open Source - Page 3 - DisplayLink Forum

however according to below link:

DisplayLink Linux Driver | That would be nice

Best regards
igor

Re: USB display with displaylink issue

wangvictor — Tue, 27 Feb 2018 02:40:44 GMT

But in my Yocto driver I found that there is a Kconfig written about displaylink.(like below content)

config FB_UDL
tristate "Displaylink USB Framebuffer support"
depends on FB && USB
select FB_MODE_HELPERS
select FB_SYS_FILLRECT
select FB_SYS_COPYAREA
select FB_SYS_IMAGEBLIT
select FB_SYS_FOPS
select FB_DEFERRED_IO
---help---
This is a kernel framebuffer driver for DisplayLink USB devices.
Supports fbdev clients like xf86-video-fbdev, kdrive, fbi, and
mplayer -vo fbdev. Supports all USB 2.0 era DisplayLink devices.
To compile as a module, choose M here: the module name is udlfb.

Is this driver doesn't support displaylink?

Re: USB display with displaylink issue

igorpadykov — Tue, 27 Feb 2018 03:21:39 GMT

suggest to post this on DisplayLink Forum,

as nxp bsps do not support it.

Best regards
igor