On Sat, 14 Apr 2012, Martin Mokrejs wrote: > I booted up 3.3.2 kernel now and ran usbmon over all USB stuff but with > unplugged mouse and keyboard so I hope there was nothing extra other than the USB > ports of the laptop itself and traffic from the USB to SATA bridge in question. > > I started up the cat command catching the usb traffic and connected the external > bridge with JMS539 chip. > > The JMS539 chip decided to spin down the disk after about 13 minutes (according to > the timestamp of the file touched last time by cat writing down the usbmonitored > data, so maybe it did not flush some stuff meanwhile?). Can't say. > > After the disk was down I ran gdisk to fetch partition table of the disk, just to > make the disk spin up again. Then I killed the cat command but maybe should have > disconnected the drive first ... to get maybe more errors into the log? ;-) The log shows that gdisk's READ command had to be issued three times. The first two times it failed after six and five seconds, respectively. Each time, the device reported Not Ready to Ready Transition. Don't ask me why this had to happen twice. But the third READ worked okay. My guess is that the bridge didn't spin down the drive. Probably the drive spun down all by itself. There's an automatic spin-down delay time that you might be able to set using hdparm. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
