Re: Pluggable frame buffer devices

On 02/16/15 16:39, Shawn Webb wrote:
> On Sunday, February 15, 2015 11:14:47 PM Hans Petter Selasky wrote:
>> Hi,
>>
>> I've added support for USB display link adapters to FreeBSD-11-current,
>> but the kernel panics once "vt_fb_attach(info)" is called from
>> "fbd_register(struct fb_info* info)" when the USB device is plugged or
>> udl.ko is loaded. Is this a known issue?
>>
>> REF: https://svnweb.freebsd.org/base/head/sys/dev/usb/video/udl.c
>>
>> --HPS
>
> I personally can't answer your question. But I'd love to help test this,
> especially since Haswell graphics isn't supported, yet, and my laptop is
> running Haswell. What would be a good USB display device to buy to help test
> this awesome work out?

Hi Shawn,

I think any USB device that uses the brand name "DisplayLink" will work.

Current list of supported devices:

> /*
>  * Matching devices.
>  */
> static const STRUCT_USB_HOST_ID udl_devs[] = {
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_LCD4300U, DL120)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_LCD8000U, DL120)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_GUC2020, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_LD220, DL165)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_VCUD60, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_DLDVI, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_VGA10, DL120)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_WSDVI, DLUNK)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_EC008, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_HPDOCK, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_NL571, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_M01061, DL195)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_NBDOCK, DL165)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_SWDVI, DLUNK)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_UM7X0, DL120)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_CONV, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_PLUGABLE, DL160)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_LUM70, DL125)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_POLARIS2, DLUNK)},
>         {USB_VPI(USB_VENDOR_DISPLAYLINK, USB_PRODUCT_DISPLAYLINK_LT1421, DLUNK)}
> };


Also see:

man udl

Some work needs to be done to fully integrate with the VT console 
subsystem. I had Xorg up and running today with the DisplayLink I 
adapter I have, and I works quite well. With USB 3.0 ones I think we can 
expect more.

--HPS