Hi Bjorn yes this that are refer, more detailed version was in previous Workshop https://indico.desy.de/getFile.py/access?contribId=5&sessionId=1&resId=0&materialId=slides&confId=7866 and additionally was presentation about driver part https://indico.desy.de/getFile.py/access?contribId=32&sessionId=9&resId=0&materialId=slides&confId=10329 I hope this will help and may be I will get some feedback to improve both and fix bugs Cheers Ludwig On 01/27/2015 05:50 PM, Bjorn Helgaas wrote: > Hi Ludwig, > > Thanks a lot for the pointers to MTCA information. I found > presentation slides here: > https://indico.desy.de/getFile.py/access?contribId=33&sessionId=0&resId=1&materialId=slides&confId=10329, > which I assume is that you're referring to. > > On Mon, Jan 26, 2015 at 1:38 AM, Ludwig Petrosyan > <ludwig.petrosyan@xxxxxxx> wrote: >> Hello >> >> (I have send this email two days ago but got status undeliverable, so try to >> send it again) >> >> We had the same problem on the MTCA system years ago, but now the problem is >> solved. >> The MTCA system is a kind of ATCA and I think attention Button problem could >> be solved in the same way. >> Ok, now what we have done: >> First of all the main difference of the ATCA or MTCA PCIe system is what the >> PCIe Switch which responsible for the HotPlug >> >> (I mean Switch which is connected to the crate slots, and hotplug >> controllers of this are used in hotpluging ) and the Attention Button of the >> >> PCIe slot reside on the different boards (usually PCIe Switch is on the >> Crate Manager board and Attention Button is the AMC module Latch ), >> >> So there are no any wired connections between Attention Button and PCIe >> Switch. Than user pool out the AMC module Latch the PCIe Switch has no idea >> >> about that, BUT the AMC module controller (MMC) sends IPMI message to the >> Crate Management Controller (MCMC) >> and MCMC starts AMC powering down procedures. The idea was: usually MCMC and >> PCIe Switch reside on the same board and MCMC getting IPMI message >> >> about state change of the AMC Latch (latch polled out or pressed) set >> appropriate registers of the PCIe Switch or push high appropriate lines of >> the PCIe Switch >> >> and PCIe Switch gets information that Attention Button is pressed and send >> hotplug interrupt to the hotplug driver. >> This approach works in our MTCA systems and we have a full working PCIe >> HotPlug. > It sounds like you basically have some IPMI glue between the the AMC > latch and the PCIe Attention Button, and from the point of view of the > pciehp (PCIe native hotplug) driver, it just sees a normal Attention > Button. That sounds like a reasonable thing to do. > > In Paulo's case, it sounds like there is some sort of switch related > to the card, but the IPMI or similar glue that could potentially lead > to the Attention Button line doesn't exist. In that case, pciehp > doesn't know anything about the switch. If there's some other way, > e.g., IPMI, to learn about the switch, maybe that could be done via a > separate driver. > >> More detailed information one can get to look documents of the MTCA Workshop >> (http://mtcaws.desy.de/) in tutorial section was presentation about >> >> PCIe Hotplug, or look in PICMIG recommendation (there is new recommendation >> about PCIe HotPlug for MTC.4) >> >> With best regards >> >> Ludwig Petrosyan >> >> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
