> -----Original Message----- > From: John Garry <john.g.garry@xxxxxxxxxx> > Sent: Wednesday, May 8, 2024 3:48 PM > To: Li, Eric (Honggang) <Eric.H.Li@xxxxxxxx>; Jason Yan <yanaijie@xxxxxxxxxx>; > james.bottomley@xxxxxxxxxxxxxxxxxxxxx; Martin K . Petersen <martin.petersen@xxxxxxxxxx> > Cc: linux-scsi@xxxxxxxxxxxxxxx > Subject: Re: Issue in sas_ex_discover_dev() for multiple level of SAS expanders in a domain > > > [EXTERNAL EMAIL] > > On 08/05/2024 01:59, Li, Eric (Honggang) wrote: > >>> Call to sas_ex_join_wide_port() makes the rest PHYs associated with > >>> that existing port > >> (making it become wideport) and set up sysfs between the PHY and > >> port. > Set PHY_STATE_DISCOVERED would make the rest PHYs not being > >> scanned/discovered again (as this wide port is already scanned). > >> > >> If you can just confirm that re-adding the code to set phy_state = > >> DISCOVERED is good enough to see the SAS disks again, then this can > >> be further discussed. >> > > OK. I will work on that and keep you updated. > > I expect a flow like this for scanning of the downstream expander: > > sas_discover_new(struct domain_device *dev [upstream expander], int > phy_id_a) -> sas_ex_discover_devices(single = -1) -> > sas_ex_discover_dev(phy_id_b) for each phy in @dev non-vacant and non-discovered -> > sas_ex_discover_expander( [downstream expander]) for first phy scanned which belongs to > downstream expander. > > And following that we have continue to scan phys in sas_ex_discover_devices(single = -1) -> > sas_ex_discover_dev(phy_id_b) -> > sas_ex_join_wide_port() -> for each non-vacant and non-discovered phy in phy_id_b which > matches that downstream expander. > > Can you see why this does not actually work/occur? > before calling sas_ex_join_wide_port(), sas_dev_present_in_domain() finds the attached_sas_address of PHY (phy_id_b) is already in the domain of that root port, and then disable all PHYs to that downstream expander (in sas_ex_disable_port(dev, attached_sas_addr)) Therefore, I think we need to switch the order of function call to sas_ex_join_wide_port() and sas_dev_present_in_domain().
