Patch Name: PHKL_2102 Patch Description: S700 -- Fix "Panic: Could not stop audio dma" problem. Short Description ----------------- This bug fixes a problem that normally manifests itself as a "panic: Could not stop audio dma". As far as can be determined, this bug will only occur if the system has an Eisa card installed that masters the bus (i.e. does dma). There are even more constraints, and it is not clear that this problem will ever actually be seen. The "Long Description" below contains much more detail. DO NOT INSTALL THIS PATCH UNLESS YOU ARE ABSOLUTELY SURE THAT THE PROBLEM DESCRIPTION MATCHES YOUR PROBLEM. Long Description ---------------- WARNING ======= PLEASE DO NOT INSTALL THIS PATCH UNLESS YOU ARE SURE YOU NEED IT. Read the following description carefully to verify that the problem you are trying to solve matches the symptoms described below. Also, if you do solve a problem using this patch, please inform Monish Shah at (303)-229-6756 or e-mail monish@fc.hp.com that you have encountered the "Jupiter audio DMA problem". We really need to know that! Audio bug in models 715, 725, 735 and 755 ========================================= The CD-quality audio sub-system in models 715, 725, 735 and 755 has a bug that is excited if the system bus is held too long by any particular device. To the best of our knowledge, this can only occur if at least one EISA card is plugged into the system. Also, this EISA card must master the bus and do block mode transfers in ISA compatible mode. Although we do not know of any cards that do this, it is possible that such a card exists. If such a card is used simultaneously with the audio sub-system, the latter can malfunction and eventually cause the system to crash (with a panic message). The best way to identify this bug is to look for the following line in the panic message: Could not stop audio dma. What the bug isn't ================== Users will often notice that an audio message can break up (i.e. be interrupted) if the system is heaviliy loaded. In this context, heavy load does not necessarily refer to the CPU, it can also refer to heavy disk I/O. This is caused by the fact that a UNIX workstation is fundamentally not a real-time system. The bug described above is not responsible for this behavior. The solution described below should ONLY be used if the system has crashed with the message described above. Solution ======== Try installing this patch. If it solves your problem, please inform Monish (see above). Note that when this problem occurs, audio will break up because the bus bandwidth is being hogged by the EISA card (in ISA mode). That problem is impossible to fix. This patch will keep the system from crashing. Path Name: /hp-ux_patches/s700/9.X/PHKL_2102 Effective Date: 930212 Patch Files: /system/PHKL_2102/new/audio.o SR/APR#: None. "what" string/timestamp: audio.o: PATCH_9.01 audio.o 1.2.61.16.x.x 93/02/12 PHKL_2102 "sum" output: 3588 69 audio.o Supersedes: None Dependencies: HP-UX 9.01 Patch Package Size: 62 Kbytes Installation Instructions: Please review all instructions and the Hewlett-Packard SupportLine User Guide or your Hewlett-Packard support terms and conditions for precautions, scope of license, restrictions, and, limitation of liability and warranties, before installing this patch Note: Please back up your system before you patch. ---------------------------------------------------------------------- After getting the patch onto your machine, unshar the patch (sh PHKL_2102). To install this patch do the following: 1) Run /etc/update (Note: you must be logged in as root to update a system). 2) Once in the update "Main Menu" move the highlighted line to "Change Source or Destination ->" and press "Return" or "Select Item". 3) Make sure the highlighted item in the "Change Source or Destination" window is "From Tape Device to Local System ...", the press "Return" or "Select Item". 4) You should now be in the "From Tape Device to Local System" window. Change the "Source: /dev/rmt/0m" to "Source: /tmp/PHKL_2102.updt" (this assumes that you are in the /tmp directory where PHKL_2102.updt has been placed). Note: You must enter the complete path name. 5) Press "Done". 6) From here on follow the standard directions for update. The customized script that update runs will move the original software to /system/PHKL_2102/orig. HP recommends keeping this software there in order to recover from any potential problems. It is also recommend that you move the PHKL_2102.text file to /system/PHKL_2102 to be retained for future reference. If you wish to put this patch on a magnetic tape and update from the tape drive, dd a copy of the patch to the tape drive. As an example the following will create a copy of the patch that update can read: dd if=PHKL_2102.updt of=/dev/rmt/0m bs=2048