On 13/06/2024 13:23, Xingui Yang wrote:
Sorry for delay in responding and asking further questions.
We found that it is judged as broadcast flutter when the exp-attached end
device reconnects after probe failed, as follows:
[78779.654026] sas: broadcast received: 0
[78779.654037] sas: REVALIDATING DOMAIN on port 0, pid:10
[78779.654680] sas: ex 500e004aaaaaaa1f phy05 change count has changed
[78779.662977] sas: ex 500e004aaaaaaa1f phy05 originated BROADCAST(CHANGE)
[78779.662986] sas: ex 500e004aaaaaaa1f phy05 new device attached
[78779.663079] sas: ex 500e004aaaaaaa1f phy05:U:8 attached: 500e004aaaaaaa05 (stp)
[78779.693542] hisi_sas_v3_hw 0000:b4:02.0: dev[16:5] found
[78779.701155] sas: done REVALIDATING DOMAIN on port 0, pid:10, res 0x0
[78779.707864] sas: Enter sas_scsi_recover_host busy: 0 failed: 0
...
[78835.161307] sas: --- Exit sas_scsi_recover_host: busy: 0 failed: 0 tries: 1
[78835.171344] sas: sas_probe_sata: for exp-attached device 500e004aaaaaaa05 returned -19
[78835.180879] hisi_sas_v3_hw 0000:b4:02.0: dev[16:5] is gone
[78835.187487] sas: broadcast received: 0
[78835.187504] sas: REVALIDATING DOMAIN on port 0, pid:10
[78835.188263] sas: ex 500e004aaaaaaa1f phy05 change count has changed
[78835.195870] sas: ex 500e004aaaaaaa1f phy05 originated BROADCAST(CHANGE)
[78835.195875] sas: ex 500e004aaaaaaa1f rediscovering phy05
[78835.196022] sas: ex 500e004aaaaaaa1f phy05:U:A attached: 500e004aaaaaaa05 (stp)
[78835.196026] sas: ex 500e004aaaaaaa1f phy05 broadcast flutter
[78835.197615] sas: done REVALIDATING DOMAIN on port 0, pid:10, res 0x0
The cause of the problem is that the related ex_phy's attached_sas_addr was
not cleared after the end device probe failed. In order to solve the above
problem, a function sas_ex_unregister_end_dev() is defined to clear the
ex_phy information and unregister the end device after the exp-attached end
device probe failed.
Can you just manually clear the ex_phy's attached_sas_addr at the
appropiate point (along with calling sas_unregister_dev())? It seems
that we are using heavy-handed approach in calling
sas_unregister_devs_sas_addr(), which does the clearing and much more.
As devices may probe failed after done REVALIDATING DOMAIN when call
sas_probe_devices(). Then after its port is added to the sas_port_del_list,
the port will not be deleted until the end of the next REVALIDATING DOMAIN
and sas_destruct_ports() is called. A warning about creating a duplicate
port will occur in the new REVALIDATING DOMAIN when the end device
reconnects. Therefore, the previous destroy_list and sas_port_del_list
should be handled after devices probe failed.
Signed-off-by: Xingui Yang <yangxingui@xxxxxxxxxx>
---
Changes since v2:
- Add a helper for calling sas_destruct_devices() and sas_destruct_ports(),
and put the new call at the end of sas_probe_devices() based on John's
suggestion.
Changes since v1:
- Simplify the process of getting ex_phy id based on Jason's suggestion.
- Update commit information.
---
drivers/scsi/libsas/sas_discover.c | 32 +++++++++++++++++++-----------
drivers/scsi/libsas/sas_expander.c | 8 ++++++++
drivers/scsi/libsas/sas_internal.h | 6 +++++-
3 files changed, 33 insertions(+), 13 deletions(-)
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 8fb7c41c0962..8c517e47d2b9 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -17,6 +17,22 @@
#include <scsi/sas_ata.h>
#include "scsi_sas_internal.h"
+static void sas_destruct_ports(struct asd_sas_port *port)
+{
+ struct sas_port *sas_port, *p;
+
+ list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
+ list_del_init(&sas_port->del_list);
+ sas_port_delete(sas_port);
+ }
+}
+
+static void sas_destruct_devices_and_ports(struct asd_sas_port *port)
"and" in a function name never sounds right.
Can you just call sas_destruct_port(), as it takes a port arg? Maybe
rename sas_destruct_ports() to sas_delete_ports(), as it does "delete" -
this may avoid some confusion in names.
+{
+ sas_destruct_devices(port);
+ sas_destruct_ports(port);
+}
+
/* ---------- Basic task processing for discovery purposes ---------- */
void sas_init_dev(struct domain_device *dev)
@@ -226,6 +242,9 @@ static void sas_probe_devices(struct asd_sas_port *port)
else
list_del_init(&dev->disco_list_node);
}
+
+ /* destruct devices and ports after probe failed */
+ sas_destruct_devices_and_ports(port);
}
static void sas_suspend_devices(struct work_struct *work)
@@ -350,16 +369,6 @@ void sas_destruct_devices(struct asd_sas_port *port)
}
}
-static void sas_destruct_ports(struct asd_sas_port *port)
-{
- struct sas_port *sas_port, *p;
-
- list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
- list_del_init(&sas_port->del_list);
- sas_port_delete(sas_port);
- }
-}
-
static bool sas_abort_cmd(struct request *req, void *data)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
@@ -538,8 +547,7 @@ static void sas_revalidate_domain(struct work_struct *work)
out:
mutex_unlock(&ha->disco_mutex);
- sas_destruct_devices(port);
- sas_destruct_ports(port);
+ sas_destruct_devices_and_ports(port);
sas_probe_devices(port);
}
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 4e6bb3d0f163..09be69ea09a2 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -1878,6 +1878,14 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent,
}
}
+void sas_ex_unregister_end_dev(struct domain_device *dev)
+{
+ struct domain_device *parent = dev->parent;
+ struct sas_phy *phy = dev->phy;
+
+ sas_unregister_devs_sas_addr(parent, phy->number, true);
+}
+
static int sas_discover_bfs_by_root_level(struct domain_device *root,
const int level)
{
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 85948963fb97..caeda847c919 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -50,6 +50,7 @@ void sas_discover_event(struct asd_sas_port *port, enum discover_event ev);
void sas_init_dev(struct domain_device *dev);
void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev);
+void sas_ex_unregister_end_dev(struct domain_device *dev);
void sas_scsi_recover_host(struct Scsi_Host *shost);
@@ -145,7 +146,10 @@ static inline void sas_fail_probe(struct domain_device *dev, const char *func, i
func, dev->parent ? "exp-attached" :
"direct-attached",
SAS_ADDR(dev->sas_addr), err);
- sas_unregister_dev(dev->port, dev);
+ if (dev->parent && !dev_is_expander(dev->dev_type))
+ sas_ex_unregister_end_dev(dev);
+ else
+ sas_unregister_dev(dev->port, dev);
}
static inline void sas_fill_in_rphy(struct domain_device *dev,
