On 24/11/2023 02:27, yangxingui wrote:
We already do this in sas_ex_join_wide_port(), right?
No, If the addr of ex_phy matches dev->parent, sas_ex_join_wide_port()
will not be called, but sas_add_parent_port() will be called as follows:
static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
{
struct expander_device *ex = &dev->ex_dev;
struct ex_phy *ex_phy = &ex->ex_phy[phy_id];
struct domain_device *child = NULL;
int res = 0;
<...>
/* Parent and domain coherency */
if (!dev->parent && sas_phy_match_port_addr(dev->port, ex_phy)) {
sas_add_parent_port(dev, phy_id);
return 0;
}
if (dev->parent && sas_phy_match_dev_addr(dev->parent, ex_phy)) {
sas_add_parent_port(dev, phy_id);
if (ex_phy->routing_attr == TABLE_ROUTING)
sas_configure_phy(dev, phy_id,
dev->port->sas_addr, 1);
return 0;
}
<...>
}
I am not saying that what we do now does not have a problem - I am
just trying to understand what currently happens
ok, because ex_phy->port is not set when calling sas_add_parent_port(),
when deleting phy from the parent wide port, it is not removed from the
phy_list of the parent wide port as follows:
static void sas_unregister_devs_sas_addr(struct domain_device *parent,
int phy_id, bool last)
{
<...>
// Since ex_phy->port is not set, this branch will not be enter
But then how does this ever work? It is because we follow path
sas_rediscover_dev() -> sas_discover_new() -> sas_ex_discover_devices()
-> sas_ex_discover_dev() -> sas_add_parent_port(), and not
sas_rediscover_dev() -> sas_discover_new() -> sas_ex_join_wide_port()?
If so, is that because ephy->sas_attached_phy == 0 in sas_discover_new()
-> sas_ex_join_wide_port() and it fails?
BTW, about something mentioned earlier - adding the phy19 with SAS_ADDR
= 0 ever to a sas_port seems wrong.
if (phy->port) {
sas_port_delete_phy(phy->port, phy->phy);
sas_device_set_phy(found, phy->port);
if (phy->port->num_phys == 0) {
list_add_tail(&phy->port->del_list,
&parent->port->sas_port_del_list);
if (ex_dev->parent_port == phy->port)
ex_dev->parent_port = NULL;
}
phy->port = NULL;
}
}
Thanks,
John
