[maemo-developers] N900: Mapper, device deadlocks and clutter/GL errors

[From: Eero Tamminen]

Hi,

ext Alberto Mardegan wrote:
> Hi all,
>    I've some issue with Maemo Mapper which I cannot solve by myself and are 
> unfortunately quite severe:
> 
> - Sometimes, a "HWRecoveryResetSGX: SGX Hardware Recovery triggered" line 
> appears on the syslog. Most of the times, without any visible effects.

It means that SGX HW got into state from which it cannot recover, so it
reseted itself.  When that happens, the current SGX HW state is lost.


> - Rarely, the device freezes for several seconds. It seems to me that this is 
> solved by pressing the power key and waiting a few seconds -- but it might be 
> just a coincidence.

When that happens, it can (will) cause temporary slowdown on display
updates.


> - Always: when I'm drawing on a texture (either loading a map tile, or using 
> cairo on a texture) and a Hildon banner/notification appears (either from Mapper 
> itself, or even an incoming chat notification), the texture is corrupted, and it 
> will contain a small rectangle with pseudorandom pixels.

And the graphics being drawn when the SGX HW reset happened can be
corrupted (as the operation was interrupted and state before the reset
isn't recoverable).


> I'm using clutter 1.0, from extras-devel.
> 
> When running the application in Scratchbox i486 with valgrind, it is damn slow 
> but I don't see any errors reported while rendering the tiles.
> 
> Can you help me to debug this? I suspect it is all due to some bugs in clutter 
> (or maybe in the SGX driver), but I have no idea where to start from.

It's currently assumed to be a SGX driver issue[1].  As it's non-
reproducible, it's hard to get it fixed _and_ to be verified to be
fixed.  The next release will have an updated SGX driver with changes
which which should at least make the issue much rarer.

Note that on most(?) devices it doesn't seem to happen at all, at least
with the pre-installed software.

But e.g. the 3rd party Maep application seems to make triggering of this
issue (at least on some devices) easier, especially as/when it's doing
window updates even when it's not visible (which is a clear use-time
and resource usage bug in Maep).


	- Eero

[1] See e.g. https://bugs.maemo.org/show_bug.cgi?id=9150