Hi Jeff and Tejun: I want to continue this discussion with some questions: > From: Tejun Heo wrote: > Jeff Garzik wrote: > > Shane Huang wrote: > >> 1. If users unplug one SATA HDD(no-root partition) or SATA ODD when > >> the system is running, then plug it back to the same SATA port, > >> Should the system and SATA HDD/ODD still work well? > > > > Yes. > > To add a bit, libata hotplug has grace time of at least 15secs. If the > same device is plugged out and then plugged in in that time, libata > considers that the device and/or connection has suffered transient > failure and assumes it's the same device and there's no modification to > its content. > > This means that if you disconnect a harddrive, write to it and then > connect it back in the grace period corruption will occur. It will be > fun to have some sort of competition to actually do this. :-) > > >> These questions come up when our QA test our SB700 SATA drivers, > >> but I don't know the SATA hotplug support in linux 2.6. > >> Is there any guy who can give some official confirmation? :-) > > > > The main thing of note with regards to hotplug is that the associated > > device (/dev/sdb, /dev/scd0, etc.) may change between plug and unplug. > > For example, if you unplug a SATA HDD then plug it back in, the user > > might see /dev/sdb disappear, and /dev/sdd appear -- even if it is the > > exact same HDD, on the exact same port. > > Yeah, using LABEL and/or UUID is a good idea. In the future, it will be > nice to have persistent block device name as netdevices do. When I disconnect SATA ODD and plug it back to the same SATA port after several seconds, it can still work well. But if I plug it to a different SATA port, it will NOT able to work any more. I will attach the log messages at the end of this mail, please check them. My Env: SB700 + RS780, openSUSE10.3 i386. I also find the same symptom on Intel E210882 (ICH5) under RedHat RHEL4U5. That's to say failure of SATA hotplug to different ports also exist on some Intel platforms. Do you guys think it's normal? It not, how to make SATA hotplug work on different SATA port? Should it be supported by BIOS or hardware? ====== plug SATA ODD to the original port, still can work ========= Dec 18 15:06:29 linux-i276 kernel: ata3: exception Emask 0x10 SAct 0x0 SErr 0x90200 action 0xe frozen Dec 18 15:06:29 linux-i276 kernel: ata3: irq_stat 0x00400000 , <PHY RDY changed> Dec 18 15:06:29 linux-i276 kernel: ata3: hard resetting link Dec 18 15:06:30 linux-i276 kernel: ata3: SATA link down (SStatus 0 SControl 300) Dec 18 15:06:30 linux-i276 kernel: ata3: failed to recover some devices, retrying in 5 secs Dec 18 15:06:35 linux-i276 kernel: ata3: hard resetting link Dec 18 15:06:35 linux-i276 kernel: ata3: SATA link down (SStatus 0 SControl 300) Dec 18 15:06:35 linux-i276 kernel: ata3: limiting SATA link speed to 1.5 Gbps Dec 18 15:06:35 linux-i276 kernel: ata3.00: limiting speed to UDMA/33:PIO3 Dec 18 15:06:35 linux-i276 kernel: ata3: failed to recover some devices, retrying in 5 secs Dec 18 15:06:40 linux-i276 kernel: ata3: hard resetting link Dec 18 15:06:41 linux-i276 kernel: ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 310) Dec 18 15:06:41 linux-i276 kernel: ata3.00: configured for UDMA/33 Dec 18 15:06:41 linux-i276 kernel: ata3: EH pending after completion, repeating EH (cnt=4) Dec 18 15:06:41 linux-i276 kernel: ata3: exception Emask 0x10 SAct 0x0 SErr 0x40c0000 action 0xb Dec 18 15:06:41 linux-i276 kernel: ata3: irq_stat 0x00000040 , <connection status changed> Dec 18 15:06:42 linux-i276 kernel: ata3: soft resetting link Dec 18 15:06:42 linux-i276 kernel: ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 310) Dec 18 15:06:42 linux-i276 kernel: ata3.00: configured for UDMA/33 Dec 18 15:06:42 linux-i276 kernel: ata3: EH complete ====== plug SATA ODD to a different SATA port, can NOT work ========= Dec 18 15:09:10 linux-i276 kernel: ata3: exception Emask 0x10 SAct 0x0 SErr 0x90200 action 0xe frozen Dec 18 15:09:10 linux-i276 kernel: ata3: irq_stat 0x00400000 , <PHY RDY changed> Dec 18 15:09:10 linux-i276 kernel: ata3: hard resetting link Dec 18 15:09:10 linux-i276 kernel: ata3: SATA link down (SStatus 0 SControl 310) Dec 18 15:09:10 linux-i276 kernel: ata3: failed to recover some devices, retrying in 5 secs Dec 18 15:09:15 linux-i276 kernel: ata3: hard resetting link Dec 18 15:09:16 linux-i276 kernel: ata3: SATA link down (SStatus 0 SControl 310) Dec 18 15:09:16 linux-i276 kernel: ata3.00: limiting speed to UDMA/33:PIO2 Dec 18 15:09:16 linux-i276 kernel: ata3: failed to recover some devices, retrying in 5 secs Dec 18 15:09:21 linux-i276 kernel: ata3: hard resetting link Dec 18 15:09:21 linux-i276 kernel: ata3: SATA link down (SStatus 0 SControl 310) Dec 18 15:09:21 linux-i276 kernel: ata3.00: disabled Dec 18 15:09:21 linux-i276 kernel: ata3: EH complete Dec 18 15:09:21 linux-i276 kernel: ata3.00: detaching (SCSI 2:0:0:0) Dec 18 15:09:22 linux-i276 kernel: scsi 2:0:0:0: rejecting I/O to dead device Thanks Shane - 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
