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().
Hi Eric,
Can you test the following patch to see if it works?
Author: Jason Yan <yanaijie@xxxxxxxxxx>
Date: Sat May 11 11:33:35 2024 +0800
scsi: libsas: Skip disable PHYs which can form wide ports
Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
diff --git a/drivers/scsi/libsas/sas_expander.c
b/drivers/scsi/libsas/sas_expander.c
index f6e6db8b8aba..39a86857bc52 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -618,15 +618,17 @@ static void sas_ex_disable_port(struct
domain_device *dev, u8 *sas_addr)
}
}
-static int sas_dev_present_in_domain(struct asd_sas_port *port,
+static int sas_dev_present_in_domain(struct domain_device *dev,
u8 *sas_addr)
{
- struct domain_device *dev;
+ struct domain_device *tmp;
if (SAS_ADDR(port->sas_addr) == SAS_ADDR(sas_addr))
return 1;
- list_for_each_entry(dev, &port->dev_list, dev_list_node) {
- if (SAS_ADDR(dev->sas_addr) == SAS_ADDR(sas_addr))
+ list_for_each_entry(tmp, &dev->port->dev_list, dev_list_node) {
+ if (tmp->parent == dev)
+ continue;
+ if (SAS_ADDR(tmp->sas_addr) == SAS_ADDR(sas_addr))
return 1;
}
return 0;
@@ -973,7 +975,7 @@ static int sas_ex_discover_dev(struct domain_device
*dev, int phy_id)
return 0;
}
- if (sas_dev_present_in_domain(dev->port, ex_phy->attached_sas_addr))
+ if (sas_dev_present_in_domain(dev, ex_phy->attached_sas_addr))
sas_ex_disable_port(dev, ex_phy->attached_sas_addr);
if (ex_phy->attached_dev_type == SAS_PHY_UNUSED) {
