I actually have a lot of information I can share about this since I wrote this email. To be brief, the sas2ircu toolset works perfectly fine with IT mode HBAs - just not with passive backplanes AFAICS [e.g. the 846A, versus the 846EL2]. Also, the bug I'm experiencing is not present with the SAS2308 generation of the HBAs (the 9217 and friends) at the same F/W version as the 9211, so this may be a bug - on the controller chip, driver, or HBA firmware. - Rich On Sat, Aug 18, 2012 at 7:52 PM, Pasi Kärkkäinen <pasik@xxxxxx> wrote: > On Tue, Jul 03, 2012 at 09:54:58PM -0400, Rich wrote: >> [My apologies if this is the wrong mailing list for this, but it >> seemed to be the most relevant. Please direct me elsewhere and discard >> if this is OT.] >> > > This is a perfectly fine list, hopefully :) > >> Hi all, >> > > Hello, > >> I've been beating my head against SGPIO for a bit now, and I can't >> tell if I'm just misreading SFF-8485, or this backplane is just not >> doing something sane. >> > > I've been struggling with SGPIO LED control aswell! > >> I have here a Supermicro X8DAH-F+ with a backplane of model >> BPN-SAS-836A - which means it has 3 MG9072 controller chips on it. >> Supports speaking in-band or out-of-band to read data, control lights, >> &c. >> >> With two LSI 9201-16i HBA attached, manipulating it via >> /dev/bsg/sas_hostN and smp_utils 0.97, SFF-8485 section 8.4.4 seems to >> think that changing this: >> 00 41 02 00 00 a0 a0 a0 a0 a0 a0 a0 a0 a0 a0 a0 a0 >> 10 a0 a0 a0 a0 00 00 00 00 00 00 00 00 00 00 00 00 >> 20 00 00 00 00 >> >> By doing this: >> # smp_write_gpio -d a1,a0,a0,a0 -t 3 -i 0 -c /dev/bsg/sas_hostN >> >> Resulting in: >> 00 41 02 00 00 a1 a0 a0 a0 a0 a0 a0 a0 a0 a0 a0 a0 >> 10 a0 a0 a0 a0 00 00 00 00 00 00 00 00 00 00 00 00 >> 20 00 00 00 00 >> >> Should enable a single drive's fault LED (drive m+3, by spec above). >> > > Wow, I've been trying to figure out how to control SGPIO from Linux, > and for some reason I didn't find anything about smp_write_gpio earlier. > > I need to try that. Thanks a lot for this information! :) > > (earlier I tried getting LSI sas2ircu to do something clever > with the LEDS but that didn't work at all - I guess LSI only supports > SGPIO LED control in IR mode - not IT mode). > > >> In practice, I am in possession of ~90 identical machines, and on >> every single one, this controls the fault LED on 3 drives - I have 3 >> SAS ports wired to the backplane (via iPASS cable) per HBA, so I would >> suspect the HBA of setting bit m+3 on each SAS port [and having each >> of its three ports running to an input controlled by a different SGPIO >> controller on the backplane]. No permutation of the register bits >> beyond the 4 bytes at index 0 changes the behavior of the LEDs that I >> can see, and the output in the beginning [a0 a0 ... 00 00 00 00] is >> what is returned on clean cold boot of the machine. >> >> In contrast, when I have an LSI 9240-8i attached, I can control >> per-drive LEDs, though the mechanism it uses for this is opaque to me >> (the megaraid_sas driver doesn't expose a virtual SAS host port like >> mpt2sas, so I am manipulating this using LSI's closed-source MegaCli >> blob); so I know it is possible, through some method, to control >> per-drive LEDs. >> >> I cannot tell, however, whether I am using smp_write_gpio incorrectly >> (either by misreading the spec or somehow abusing the virtual SAS >> port), or it's a bug somewhere (be it in smp_write_gpio, the kernel, >> the HBA firmware, or the upstream MG9072's firmware, that is somehow >> magically avoided by the 9240-8i), and there is almost no public >> documentation of people using smp_write_gpio. >> >> I've tried this with kernel 2.6.32-220.7.1.el6, 3.4.4, and 3.5.0-rc5 >> (the last because it includes mpt2sas 13.XX.XX.XX, while 3.4.4 has >> 12.XX.XX.XX, and I was curious if anything had changed), and smp_utils >> 0.97. >> >> I wanted to see what the register state was when the 9240-8i was in >> use, but I couldn't coax the megaraid_sas driver into disgorging this >> information, and upon unplugging the iPASS cable from the backplane to >> connect it to the HBA, the backplane appears to reset its internal >> state; the LEDs cease blinking in any pattern, and consequent querying >> with the HBA returns expected default initial state. >> >> Am I insane, or is this backplane crazy? Does anyone have any >> experience with cajoling such things into submission? >> > > Hmm, I have some servers with LSI 9211-8i SAS2 HBAs (mpt2sas driver) > and Supermicro BPN-SAS-846A backplanes, which have 3x MG9072 chips in them. > > I'll let you know how that stuff works for me! > > Thanks, > > -- Pasi > -- 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
