On Sat, Jan 16, 2010 at 12:02 PM, Krzysztof Halasa <khc@xxxxxxxxx> wrote: > 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. Well, it is possible there is some kind of flaw in the JMB363 chip itself that causes this problem. (Could be it happens in Windows too, I don't think Windows drivers normally report these kinds of events anywhere and if it never reached the point of actually deciding a device was connected, you likely wouldn't notice.) I suppose we could add a workaround in the driver to ignore hotplug events, but then real hotplug events wouldn't get handled properly.. What revision does your JMB363 report in lspci? Mine shows: 03:00.0 SATA controller: JMicron Technologies, Inc. 20360/20363 Serial ATA Controller (rev 03) (prog-if 01 [AHCI 1.0]) Tejun, any other ideas? -- 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
