Hi Arie, I just wanted to let you know, that you exactly hit the mark with your assumption regarding the priority registers below.
Thank you very much! Some details for the list: Due to a silicon bug in DM6443 rev 1.3 the default value 0x00040444 was used for register MSTPRI0 (see silicon errata for details). This register is responsible for "Switched Central Resource (SCR) Bus Priorities". This register was not initialized in our firmware at all. The default value just worked fine. In silicon rev 2.1 this bug has been fixed and thus the default value has changed to 0x00050111. For us this value caused the problem I described below. Now I'm setting the register to 0x00040444 in u-boot explicitly and everything works fine for silicon rev 2.1 as well. Thanks again! Kind regards Thomas -----Ursprüngliche Nachricht----- Von: Arie Muijnck [mailto:amuij...@optelecom-nkf.com] Gesendet: Dienstag, 23. März 2010 17:37 An: DISTEC Kloiber Thomas; davinci-linux-open-source@linux.davincidsp.com Betreff: RE: Audio dropouts since using DM6443 silicon rev. 2.1 In the 2.1 revision the priority registers have been improved. In the old version there was a bug: all peripherals used the bits of one register, the other was unused. Now they are properly connected, but the default values of peripheral priorities are thus not the same as the old 1.3 silicon. To restore the previous 1.3 priority situation our bootloader just writes V1.3 equivalent values into both registers. Maybe this is also your problem. Kind regards, Arie de Muijnck -----Original Message----- From: davinci-linux-open-source-boun...@linux.davincidsp.com [mailto:davinci-linux-open-source-boun...@linux.davincidsp.com] On Behalf Of DISTEC Kloiber Thomas Sent: Tuesday, March 23, 2010 15:38 To: davinci-linux-open-source@linux.davincidsp.com Subject: Audio dropouts since using DM6443 silicon rev. 2.1 Hi, I have a custom board with DaVinci DM6443 with kernel TI LSP 2.0.0.140 (MV 2.6.18), DVSDK 2.0.0.22 and TI gStreamer for video / audio playback. In parallel to the playback there is a HTTP and a FTP server running on the ARM. The HTTP server is used to configure the board via web browser and the FTP server is used to do content uploads. Now I received the first boards with silicon rev 2.1 (TMS320DM6443A). All these boards have the same problem. When the HTTP server (as long as the user is configuring the board) or FTP server (as long as the user is uploading new content) is working in parallel to video playback, I get audio dropouts at the line out. Just doing video / audio playback works fine. I guess, this has something to do with the extra system load caused by the servers. Playing around with nice levels of the servers did not help. I don't have this problem with silicon revision 1.3. The only difference between both systems is just the silicon rev. of the DaVinci (same hardware, same firmware). I found this in the Silicon Errata: http://focus.ti.com/lit/er/sprz240m/sprz240m.pdf Page 8: 2.1.3 Audio Serial Port (ASP) Transfers Should be Buffered in Internal Memory For me it seems, this issue might be the root cause for the problem I came across? I guess, TI LSP doesn't use the internal memory to buffer audio? At least I didn't find it... I currently don't understand, why I have this problem with silicon rev 2.1 only. Does this make sense? In the archive of this list I found some patches for git kernel, which introduced usage of internal memory to avoid underrun on audio. I guess, this is what have to implement on my kernel as well? Has anyone done this before for MV 2.6.18 ? Unfortunately, I don't have the resources to switch to the git kernel at the moment. And AFAIK, video playback on DM644x is still not supported by TI DVSDK with git kernel. Thanks in advance! Kind regards Thomas _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
