On Wed, 2005-10-05 at 16:19 -0700, Luben Tuikov wrote: > I'd like to move sas_do_lu_discovery(struct domain_device *dev) > into SCSI Core (as the comment therein says), for _new_ (non-legacy) > devices, i.e. with newer FW. Initially my reaction is not for the time being, for two reasons 1. The domain device as you have implemented it requires a lot of infrastructure support. I'd like to see this refined in the transport classes to hone it before considering pulling it into the mid-layer 2. sas_do_lu_discovery() duplicates a lot of existing functionality, but also lacks a lot of quirk processing. I know the argument is that SAS won't have any quirks, but I'd like to have this proven in the field before I take it as read. > It also handles devices who do not even respond > to REPORT LUNS on either LU 0 or RL WLUN (like early prototype > SES FW), in which case it would register LU 0 for them since > this is where tasks are sent. I'm sure you're aware that not responding on either LUN 0 or the report luns WLUN is a violation of SAM ... however, if we really already have broken SAS devices with this problem, then you're welcome to expand scsi_scan_target() to cope. WLUN support is really the only piece that scsi_scan_target() doesn't currently possess and, as has been discussed before, that only really matters if we get a target that's not going to respond to an INQUIRY on LUN0 (I expect most of them, even if they have no LUN0 will respond with PQ 3 to the inquiry and thus be caught by scsi_scan_target() anyway). However, to add WLUN support to scsi_scan_target() looks pretty simple: If the transport supports > 256 LUNs and the initial INQUIRY comes back SCSI_SCAN_NO_RESPONSE then fire off a WLUN report lun scan anyway. By all means, submit a patch to do this. > P.S. REPORT LUNS is Mandatory as per SPC, so newer devices > (SAS) support it. Furthermore if their LUs are sparse they > (really) support REPORT LUNS. Actually, it's optional per SPC; it's mandatory in SPC-2 but *only* if your device is multi-LUN; and it finally became mandatory for everything in SPC-3 (or I should say "becomes" since SPC-3 isn't ratified yet). James - : 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
