Hi, finally we got a time slot tomorrow to do the next soldering tests for the GTA04A5. The reason why it took so long is that these pick&place machines sometimes run for several days with the same program producing some 10 thousand PCBs for other customers...
So they can't easily stop and do experiments like we need. The plan for tomorrow is try to solder 4 PoP systems with different preparation: 1. without (almost no) solder paste and no flux. The idea is to see if the effect comes from too much flux added or is inherent to the DM3730 package. 2. with solder paste in the outer ring of the DM3730 package and no paste in the middle (where the shorts usually occur). The idea is to reduce the amount of flux in the critical area. 3. with a tiny snippet of Kapton under the DM3730 and doing the same flux dipping as we tried before. 4. with a tiny snippet of Kapton under the DM3730 and full solder paste as one would usually do. Puh. Quite costly to produce scrap since we will not solder any other components and therefore we can only do X-ray inspection and measure for short circuits. There is no possibility to test if the DM3730 SoC would work well and has really all pads connected. Anyways I hope this will give a lot of insights and finally will allow to decide how to do the real production run. Probably we need to run 4 full boards and test them before doing the remaining ones... On the kernel side there is also some news. Nothing for those readers who are strong advocates of FLOSS and do never want to run any binary from unknown sources. Those can skip this section... The reason is that it is about the PVR/SGX530 3D GPU inside the DM3730 chip. The whole 3D system is made of four components, two of them are binary blobs only, one is GPL open source and the fourth unknown is the SGX hardware. The news is about the open source kernel driver. I have finally managed to get it compiled again on letux-4.9-rc2. And in a way that it is a simple kernel module. Well, if you want to call a 4 MByte .ko "simple". modprobing on the GTA04 almost succeeds, except an error message from the "reset framework". This was expected, since it is one of two parts which need adaptation to newer kernel APIs. One is the "reset framework" and the other one is about dma/cache interaction where the TI driver calls some very very low level (even assembler) code directly. This has been declared private API some time ago and so it has to be rewritten to use some more official API. If someone wants to dig into this topic, the source code is here: http://git.goldelico.com/?p=gta04-kernel.git;a=shortlog;h=refs/heads/work/hns/gpu/pvr-v2 Now back to the topic of FLOSS. This driver is of course free. But it will need / load firmware binaries into the GPU part of the SoC. These binaries are on one hand some "microkernel" running on the SGX GPU and the ARM libraries for OpenGL etc. So thats it for today. And I hope I can bring some news about the GTA04A5 tomorrow. BR, Nikolaus _______________________________________________ Community mailing list Community@openphoenux.org http://lists.goldelico.com/mailman/listinfo.cgi/community http://www.tinkerphones.org