On 2024/5/8 16:29, Li, Eric (Honggang) wrote:
-----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().
If this is true then all cascaded expanders will have this issue, I
wonder why the test guys have not report it until now.
Thanks,
Jason
祝一切顺利
