[Gta04-owner] Letux Kernel for GTA04 and Pyra - 4.3-rc1 and 4.2

Dr. H. Nikolaus Schaller hns at goldelico.com
Tue Sep 15 07:46:51 CEST 2015

Hi all,
we have started to upgrade to kernel 4.3-rc1 but have more problems than ever.

There have been changes in some OMAP regulator initialization (pbias) code
which is now broken. Maintainers tell us that some required patches are
not yet in rc1 and some are not even queued up for Linus.

Next there are problems with omap-hsmmc, the driver for the MMC interfaces
we need for the µSD card with our OS and for accessing the WiFi chip. We currently
need a workaround to make it boot at all.

There has also been a rewrite of the twl4030_charger code and that appears to
be broken. It does not boot well (modprobe timeouts) and thus makes the boot
process hang for a minute or so. As a consequence neither USB is working nor
is the battery charging. This makes debugging without a big pile of pre-charged
batteries a little difficult :)

So 4.3-rc1 is far away from being useable… But we work on it to help to get it

Kernel 4.2 has got some really important fix: we have finally managed to solve the
X-server crash issue that was known in all kernels since ca. 3.15. The symptom was
that too heavy use of the touch screen made the server segfault.


The reason is neither our touch screen driver (which I did suspect) nor the
X-server but a problem in kernel signal delivery and switching between THUMB
and ARM code. X-servers uses SIGIO and SIGALRM to handle input device events
and if they arrive in the wrong moment, the ARM CPU tries to resume in the
wrong mode. But only if we have a multi-architecture kernel like we have because
we want to support different hardware models (and ARM CPU variants).

Then, we have fixed the wlan interface so that it is back after boot.

And, we have started the transition to the “Letux Distribution” name. This e.g.
means that the “goodies” directory (scripts, udev rules etc.) is no longer in
src/GTA04/ but src/Letux/ and the config is now letux_defconfig.

And finally it supports the new Pyra CPU-Board (OMAP5) as well.

Please test the 4.2 kernel. It is here:


A description how to compile can be found here:



PS: donations are welcome: <http://shop.goldelico.com/wiki.php?page=GTA04%3ADonation>

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