Robert Hancock <hancockrwd@xxxxxxxxx> writes: > Hmm.. From those test results I really suspect some kind of hardware > fault. Could be a defective motherboard - I don't know if that chip > needs any terminating resistors on the motherboard for the SATA signal > lines or something, if so, could be they weren't installed properly.. Unfortunately I can't find a JMB363 datasheet on the net, but there is a certain mb (p965t-a) schematic available. It seems JMB363 doesn't need terminators on SATA RX/TX lines, there is capacitative coupling only (10 nF in each line). The port in question (SATA#2) on my mb (P45 Neo2) uses pins 56 (RXP) 57 (RXN) and 60 (TXN) 61 (TXP). No visible irregularity, the traces look like they should, go straigt to the capacitors, and then to 0R R-packs and to the connector. It looks exactly the same for both ports. There is no short circuit past the capacitors (from the connector side). I'd say quite low probability that there is something wrong with these signals. It seems the chip uses extra 12k resistors for SATA (p965t-a calls the pins SJ_REXT[12]), pin 44 for port#1 and 55 for port#2. Both look sane. I will check the suspected connections with the machine powered off later. The RX and TX trace pairs go next to each other for up to 10 mm, could that be a problem at these frequencies? If so it would show up on all/many such boards certainly? Can't find any report. OTOH other people have similar problems with other boards: e.g. ASUS P5KC: http://ubuntuforums.org/showthread.php?t=766217 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/377633 (unknown boards) https://archlinux-fr.org/doku.php?id=securisation:logcheck http://forum.ubuntu-fr.org/viewtopic.php?pid=2739616 http://ubuntu-ky.ubuntuforums.org/showthread.php?p=7243061 The last one claims: this started after an upgrade to ubuntu 9.04 and is stll here after re-installing ubuntu 8.10. this was fixed by re-installing ubuntu 8.10 only using the kernal, 2.6.27-7-generic. I don't know if JMB36x is involved in this case, and how reliable the info is. Investigating as time permits. -- Krzysztof Halasa -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
