#9318 NORM 1.5-ATe: Via framebuffer failure on 1.5

Harald Welte hwelte at hmw-consulting.de
Wed Jun 3 03:49:35 EDT 2009

Hi Chris,

On Wed, Jun 03, 2009 at 01:59:41AM -0400, Chris Ball wrote:
> Hi Harald,
>    > this means you need to boot with vmalloc=<something-bigger>.  The
>    > framebuffer needs to be vmalloc'ed.  So if you have a relatively
>    > small amount of RAM, and the BIOS is configured for 256MB
>    > framebuffer size, the kernel-selected vmalloc area is smaller
>    > than what we need for the framebuffer.  So you have three
>    > options:
> Thanks very much; with vmalloc=256M I can use viafb from OFW.  Viafb
> takes about twenty seconds to load, perhaps because we rerouted the
> EDID pins away from the VGA connector to the panel instead..

That 20second load time is indeed very surprising, but yes, the I2C 
might be an issue, since the driver tries to probe for external TV encoders and
the like on that I2C bus.  The respective code would have to be deactivated
on a OLPC.

> OFW passes an FB size of 0x4000, which should be:
>         case 0x00004000:
>                 VideoMemSize = (64 << 20);      /*64M */

ok, that is strange.  

> (Don't worry about trying to diagnose any of this in the absence of
> hardware; it can wait until we're able to make some developer boards
> available.)

Ok, I can commit to look into all issues, i,e:
* 20second module load time
* why does it need vmalloc=
* support for your panel
once I have access to hardware.

Please contact me before you want to ship anything, as my travel schedule
determines where to send the device at which date.

- Harald Welte <hwelte at hmw-consulting.de>       http://www.hmw-consulting.de/
Consultant for Linux networking, network security, Linux driver development

More information about the Devel mailing list