Re: mpt2sas: /sysfs sas_address entries do not show individual port sas addresses.
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On 17/08/11 16:35, Douglas Gilbert wrote:
On 11-08-17 06:42 AM, Benjamin ESTRABAUD wrote:Hi,I am seing a bug with the mpt2sas driver from the "Release 18.104.22.168" kernel (commit d6c90f5b218c1ddf1496045e3939b1c960c7cb9f, tag v22.214.171.124, long termsupport kernel).I have a system that has both a LSI 1068e B3 (3G) based HBA (a SAS3801E) as well as a LSI SAS 2008 03 (6G) HBA (a SAS9200-8e). They both work as expected, but I am seeing a major difference in their respective /sysfs structure, especiallyregarding their phy's "sas_address" field, which seems to be a bug.The 3G HBA's SAS addresses are associated to a specific port in sysfs, while the6G one are associated to the actual HBA.The 3G HBA is configured to have two wide ports, made up of 4 phys each, port 0and port 1, and same configuration applies for the 6G HBA. The ports are not in "auto" nor in narrow. There are only two enabled ports on each HBA. I get the following sysfs entries regarding the 3G one:# cat /sys/class/sas_host/host5/device/phy-5\:0/sas_phy\:phy-5\:0/sas_address0x50015b2a2000060f# cat /sys/class/sas_host/host5/device/phy-5\:1/sas_phy\:phy-5\:1/sas_address0x50015b2a2000060f# cat /sys/class/sas_host/host5/device/phy-5\:2/sas_phy\:phy-5\:2/sas_address0x50015b2a2000060f# cat /sys/class/sas_host/host5/device/phy-5\:3/sas_phy\:phy-5\:3/sas_address0x50015b2a2000060f# cat /sys/class/sas_host/host5/device/phy-5\:4/sas_phy\:phy-5\:4/sas_address0x50015b2a20000613# cat /sys/class/sas_host/host5/device/phy-5\:5/sas_phy\:phy-5\:5/sas_address0x50015b2a20000613# cat /sys/class/sas_host/host5/device/phy-5\:6/sas_phy\:phy-5\:6/sas_address0x50015b2a20000613# cat /sys/class/sas_host/host5/device/phy-5\:7/sas_phy\:phy-5\:7/sas_address0x50015b2a20000613 And these ones on the 6G:# cat /sys/class/sas_host/host0/device/phy-0\:0/sas_phy\:phy-0\:0/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:1/sas_phy\:phy-0\:1/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:2/sas_phy\:phy-0\:2/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:3/sas_phy\:phy-0\:3/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:4/sas_phy\:phy-0\:4/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:5/sas_phy\:phy-0\:5/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:6/sas_phy\:phy-0\:6/sas_address0x500605b002c99150# cat /sys/class/sas_host/host0/device/phy-0\:7/sas_phy\:phy-0\:7/sas_address0x500605b002c99150As we can see above, the 3G HBA's phy "sas_address" sysfs entry displays correct information: A single SAS address for phy 0-3 and a single one for phy 4-7.As we can also see using LSIUtil, each phy is numbered from a base address andincremented.Also, the port sas address corresponds to the address of the starting phy of theport.Port0's sas address is "0x50015b2a2000060f", which corresponds to the HBA's phy0sas address.Port1's sas address is "0x50015b2a20000613" which corresponds to the HBA's phy3sas address, the starting phys for each of these ports. Output of menu "16" from LSIUtil on the 3G HBA (1068e): B___T SASAddress PhyNum Handle Parent Type 50015b2a2000060f 0001 SAS Initiator 50015b2a20000610 0002 SAS Initiator 50015b2a20000611 0003 SAS Initiator 50015b2a20000612 0004 SAS Initiator 50015b2a20000613 0005 SAS Initiator 50015b2a20000614 0006 SAS Initiator 50015b2a20000615 0007 SAS Initiator 50015b2a20000616 0008 SAS InitiatorHowever, when looking at the 6G HBA's sysfs information above, we can see that all phy's SAS address are identical, like if there was a single port made up ofthe entire 8 phys from the HBA.When looking at LSIUtil below, we get more strangeness, where all phys haveexactly the same SAS address: Output of menu "16" from LSIUtil on the 6G HBA (2008): B___T SASAddress PhyNum Handle Parent Type 500605b002c99150 0001 SAS Initiator 500605b002c99150 0002 SAS Initiator 500605b002c99150 0003 SAS Initiator 500605b002c99150 0004 SAS Initiator 500605b002c99150 0005 SAS Initiator 500605b002c99150 0006 SAS Initiator 500605b002c99150 0007 SAS Initiator 500605b002c99150 0008 SAS InitiatorBut looking at LSIUtil's menu "13" on the 6G HBA proves that we indeed have 2ports on that HBA: PhyNum Link MinRate MaxRate Initiator Target Port 0 Enabled 1.5 6.0 Enabled Disabled 0 1 Enabled 1.5 6.0 Enabled Disabled 0 2 Enabled 1.5 6.0 Enabled Disabled 0 3 Enabled 1.5 6.0 Enabled Disabled 0 4 Enabled 1.5 6.0 Enabled Disabled 1 5 Enabled 1.5 6.0 Enabled Disabled 1 6 Enabled 1.5 6.0 Enabled Disabled 1 7 Enabled 1.5 6.0 Enabled Disabled 1Somehow, on the 6G HBA using mpt2sas, all phys from a HBA seem to have the same SAS address, and all ports on that HBA, whether narrow (1Phy) or wide (4Phys),will seemingly have the same SAS address.This is causing a good few issues with our system scripting, as we relied on SASaddresses to identify ports.I searched on Google extensively before posting and couldn't find any mention ofthis issue.Is this a known issue? If so, will this be resolved in a later version of thedriver?Ben, I noticed something similar when comparing LSI 3 Gbps and 6 Gbps SAS HBAs. I was looking at the same thing but from an expander's perspective. I'm not so sure that the newer 6 Gbps HBAs are incorrect. IOW the older 3 Gbps HBAs might be playing some tricks with the HBA's SAS addresses so that it is not possible to set up a wide link spanning the lower and upper 4-phy banks (e.g. a 5 phy wide link).
Hi Doug, Thanks a lot for your reply!It is very possible indeed that this was done so that nobody would ever try to have an 8phy SAS port (possible because it couldn't handle it?), or as you said, a port spanning on 5Phys or spanning phys from two different physical ports.
Because we worked mainly with these HBAs (the 3G ones), we assumed that this was the norm in SAS: one port is issued a unique SAS address. We therefore assume that a port always has a unique SAS address and work that way, which, I find today, is probably a wrong assertion.
No real reason here, we just were working with a wrong assumption (that port sas addresses had to be unique) before. We need to update our scripts to work with ports having the same SAS address.Do you know a reason why it is not preferably for every phy on a SAS HBA to respond with the same SAS address?
LSIUtil's "Set new WWN/SAS Address" menu (and even on 6G HBA!) will request the input of a single sas address, and will set each sas phy's address differently by incrementing the user-inputed sas address. This could also be happening because LSIUtil might not have been updated fully yet.As a practical matter a SAS HBA needs a single SAS address, preferably printed on the board or its box. Then if you manage to wipe its SAS address (e.g. by erasing its flash to move from IR to IT firmware) then you know which SAS address to re-instate :-)
In fact, LSIUtil and the MPT Fusion driver used to find a HBA's sas address by doing something in the like of ioc->port->phy->sas_address (low and high), rather than reading a single ioc->sas_address value.
Thanks again for your reply, you helped me clarify some bits here.
Regards, Ben. -- 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