On Tue, Mar 22, 2011 at 03:54:40PM +0100, Herbert Poetzl wrote: > following up on a thread about PMP and SEP from earlier this > year, I have now prepared a test system which should allow > me to control all involved parts (i.e. SATA controller, PMP > and the SEP) for testing and debugging ... > during the initial system tests, I found some strange > behaviour, which I am unable to explain, and it might as > well be a SATA/PMP bug in Linux ... > the problem basically arises when I pull a drive from the > enclosure (without telling Linux first), wait some time > till the kernel becomes aware of the fact, and then put it > back into the enclosure ... > at this point, the drive indicator (PMP and the drive one) > goes on, the drive spins up, but Linux refuses to detect > the device ... I tried the following things: > echo "- - -" >/sys/class/scsi_host/host9/scan > scsiadd -s 9 > resetting the PMP (via small front panel button) > note that the target is still listed in sysfs: > # ls /sys/class/scsi_host/host9/device/ > power/ scsi_host/ subsystem@ target9:0:0/ target9:1:0/ target9:2:0/ target9:3:0/ target9:4:0/ uevent > only way to get the device back seems to be to remove the > driver (rmmod sata_sil24) and to reload it again, which is > probably a little tricky assuming that the other disks are > in use :) just for the fun of doing it, I tried to tell Linux first that the drive will be removed (via scsiadd -r) and discovered that this causes an even stranger effect: # scsiadd -r 13 4 0 0 ; seems to remove the target # scsiadd -a 13 4 0 0 ; seems to add back the target Host: scsi13 Channel: 04 Id: 00 Lun: 00 Vendor: ATA Model: ST31000340AS Rev: SD15 Type: Direct-Access ANSI SCSI revision: 05 and sometimes, the devices comes back with a different device entry but the same scsi bus/chan/id/lun, in which case, it cannot be removed via scsiadd -r anymore, as it just returns could not remove device 13 4 0 0 : No such device or address also note that this doesn't change the fact that the device is lost till the driver is reloaded once it is unplugged ... > many thanks in advance, > Herbert > -- > 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 -- 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
