Simon Farnsworth wrote: > Tejun Heo wrote: >> Simon Farnsworth wrote: >>> Tejun Heo wrote: >>>> Simon Farnsworth wrote: >>>>> Just a thought; is it possible to trigger libata EH from userspace? If >>>>> so, we could write a small utility to disable write cache, then force EH >>>>> to detect the change. >>>> That's automatically done. libata snoops cache on/off and triggers >>>> revalidation but you can request manual rescan by echoing "- - -" to >>>> /sys/class/scsi_host/hostX/scan. >>>> >>> Would it be worth changing our code to do "hdparm -W1 /dev/sda && hdparm >>> -W0 /dev/sda", or would this not show anything. The lack of revalidation >>> on some drives is what's worrying me a little here. >> Revalidation happens after cache property is changed successfully. What >> happens if you request manual rescan while the drive is not repsponding? >> > The 30 second freeze happens when we request manual rescan. We do > revalidate once the freeze is over, though; dmesg follows: Can you post dmesg with printk timestamps turned on? -- tejun - 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
