Tejun wrote: > ata4 is reporting link down and the device is detached and port > disabled afterwards. Doesn't seem to have much to do with > freezing/thawing? After all processing of a normal unplug event has completed, the port is left thawed (and the irq enabled) to allow future hotplug events on this port to be actioned. In the case of the port lockups that I have seen the port appears to be left frozen, with the irq disabled, and I am hypothesising that this is due to a race between the freeze and the thaw. Below is some additional tracing leading up to a port lockup, with some more DPRINTK statements added. The port freeze appears to be happening after the port thaw. The irq mask writes that are output by mv_set_main_irq_mask seem to show the irqs left masked off. ... __ata_port_freeze: ata4 port frozen ata_port_schedule_eh: port EH scheduled mv_set_main_irq_mask: skipped write in mv_set_main_irq_mask: 00040015, 00040015 __ata_port_freeze: ata4 port frozen ata4: hard resetting link sata_link_hardreset: ENTER sata_link_hardreset: EXIT, rc=0 ata_sff_softreset: ENTER ata_sff_softreset: about to softreset, devmask=1 ata_bus_softreset: ata4: bus reset via SRST ata_dev_classify: found ATA device by sig ata_sff_softreset: EXIT, classes[0]=1 [1]=0 mv_eh_thaw: ENTER 00040055 mv_eh_thaw: EXIT ata_eh_thaw_port: ata4 port thawed ata_std_postreset: ENTER 00040015 __ata_port_freeze: ata4 port frozen ata_port_schedule_eh: port EH scheduled ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 310) ata_std_postreset: EXIT ata_eh_revalidate_and_attach: ENTER ata_eh_revalidate_and_attach: EXIT rc=-5 ata4.00: disabled ata_eh_revalidate_and_attach: ENTER ata_eh_recover: EXIT, rc=0 ata4: EH complete ata_scsi_error: EXIT ata_scsi_hotplug: ENTER ata4.00: detaching (SCSI 3:0:0:0) ata_scsi_hotplug: EXIT The port is unresponsive at this point. And another lockup, with tracing showing entering and leaving mv_eh_freeze: ... ata_sff_tf_load: hob: feat 0x0 nsect 0x0, lba 0x0 0x0 0x0 ata_sff_tf_load: feat 0x0 nsect 0x0 lba 0x0 0x0 0x0 ata_sff_tf_load: device 0xE0 ata_sff_exec_command: ata4: cmd 0x27 mv_eh_freeze: ENTER 00040015 mv_eh_freeze: EXIT __ata_port_freeze: ata4 port frozen ata_sff_flush_pio_task: ENTER ata4.00: failed to read native max address (err_mask=0x1) ata4.00: HPA support seems broken, skipping HPA handling ata4.00: revalidation failed (errno=-5) ata4.00: disabled mv_eh_freeze: ENTER mv_set_main_irq_mask: skipped write in mv_set_main_irq_mask: 00040015, 00040015 mv_eh_freeze: EXIT __ata_port_freeze: ata4 port frozen ata4: hard resetting link sata_link_hardreset: ENTER sata_link_hardreset: EXIT, rc=0 ata_sff_softreset: ENTER ata_sff_softreset: about to softreset, devmask=1 ata_bus_softreset: ata4: bus reset via SRST ata_dev_classify: found ATA device by sig ata_sff_softreset: EXIT, classes[0]=1 [1]=0 mv_eh_thaw: ENTER 00040055 mv_eh_thaw: EXIT mv_eh_freeze: ENTER 00040015 mv_eh_freeze: EXIT __ata_port_freeze: ata4 port frozen ata_port_schedule_eh: port EH scheduled ata_eh_thaw_port: ata4 port thawed ata_std_postreset: ENTER ata4: SATA link down (SStatus 0 SControl 310) ata_std_postreset: EXIT ata_eh_revalidate_and_attach: ENTER ata_eh_recover: EXIT, rc=0 ata4: EH complete ata_scsi_error: EXIT ata_scsi_hotplug: ENTER ata4.00: detaching (SCSI 3:0:0:0) ata_scsi_hotplug: EXIT The port is unresponsive at this point. The output shows "ata_eh_thaw_port: ata4 port thawed" after the "__ata_port_freeze: ata4 port frozen", but the tracing suggests that the actual work enabling the irqs has been carried out before the irqs are subsequently disabled. Bruce. Latest News at: http://www.indigovision.com/index.php/en/news.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