Hi, John,
Thanks for your reply.
On 2024/6/18 16:55, John Garry wrote:
On 13/06/2024 13:23, Xingui Yang wrote:
Sorry for delay in responding and asking further questions.
It doesn't matter.
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.
I just tried it and it worked. If we only clear ex_phy's
attached_sas_addr, there is no need to call sas_destruct_ports(). We are
currently using sas_unregister_devs_sas_addr() which will add the port
to sas_port_del_list, so we need to call sas_destruct_ports() separately
to delete the port.
Should we also delete the port after the devices probe failed?
Maybe I can update another version and only clear ex_phy's
attached_sas_addr based on your suggestions.
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.
As described above, if we only clear ex_phy's attached_sas_addr, we do
not need to call sas_destruct_ports().
Thanks,
Xingui
