Corrupted display on XO1.5 when suspended with screen on

Walter Bender walter.bender at
Wed Jul 3 09:51:56 EDT 2013

On Tue, Jun 25, 2013 at 2:28 AM, James Cameron <quozl at> wrote:
> On Tue, Jun 25, 2013 at 12:18:43AM -0500, Sebastian Silva wrote:
>> El 21/06/13 13:56, John Watlington escribió:
>> >This is likely due to the video controller being disabled before
>> >the DCON driver has completely finished loading the image into the
>> >DCON.
>> >>Our image is based on 11.3.1 shipping firmware olpc-firmware-q3c06 (but my testing machine has q3c07 and exhibits the same malfunction).
>> >>
>> >>(...)
>> >
>> >We did some work to fix the DCON driver in newer releases.
>> >
>> So what component / package etc should I be looking to backport?
> The kernel, specifically kernel patches to the DCON driver or related
> components.
> 11.3.1 was based on kernel
> which corresponds to branch olpc-2.6.35 of the olpc-kernel repository:
> Development then switched to the branch x86-3.3, and this is where any
> DCON or display driver fixes after 11.3.1 will be found.
> I've had a quick look and these viafb fixes look relevant:
> Other than these viafb fixes, there have been no DCON driver fixes in
> x86-3.3.  I recall some fixes in the ARM laptops though.  Perhaps they
> were not backported.
> As kernel fixing can be costly for you, let me take you back a few
> steps in diagnosis ... can you confirm that the problem also affects
> the original OLPC OS 11.3.1 and not only your own build of 11.3.1?
> Does the problem only occur with automatic power management enabled?
> Is there a way to induce the problem quickly?
> It reminds me of #11231 and #10038.  You might see if the reproducers
> in those tickets cause a problem.
> Also, although we understand you cannot go to deployment phase with
> anything later than 11.3.1 because of non-technical reasons, the
> analysis of this problem could really benefit from trying to reproduce
> it with 12.1.0, 13.1.0, or 13.2.0.  If the problem does not reproduce
> in 12.1.0 for instance, it means the fix may be in that interval.  It
> would also help to exclude hardware as a cause.

You mentioned some performance issues as the principle reason for not
updating. Could you elaborate on these? It may be a better use of
resources to work on fixes those issues than trying to backport kernel



> --
> James Cameron
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Walter Bender
Sugar Labs

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