On Thu, 2010-12-09 at 10:41 -0800, Jeff Johnson wrote: > Greetings, > > Is it possible to issue a low level device reset to a PMC-Sierra PM8388 > 24x3G SAS expander using either sg3_utils or smp_utils? > > I am able to enumerate and read the status of the phys on the PM8388, > read end device information, etc. I tried sg_reset and it does a bus > reset but not an expander reset. > > Technical documentation on the PM8388 is not readily available so I do > not know if it has a mode select bit or other special method to get the > expander to reset itself. > > I am looking for an inband method to reset the expander to clear a > condition where some phys in a wide connection fail to link. A power > cycle clears the condition and I am looking to mimic a power cycle by > bouncing the expander at the lowest level possible via the SAS host > connection. There's no protocol defined way to reset an expander using SMP functions, so it's not really possible to do it in-band. It's sort of like asking if there's an ethernet packet you can send to a switch to cause it to reset. If the wide port isn't forming, you could try doing a hard reset of all the phys in the port. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
