scsi: libsas: Fix the failure of adding phy with zero-address to port

As of commit 7d1d865 ("[SCSI] libsas: fix false positive 'device
attached' conditions"), reset the phy->entacted_sas_addr address to a
zero-address when the link rate is less than 1.5G.

Currently we find that when a new device is attached, and the link rate is
less than 1.5G, but the device type is not NO_DEVICE, for example: the link
rate is SAS_PHY_RESET_IN_PROGRESS and the device type is stp. After setting
the phy->entacted_sas_addr address to the zero address, the port will
continue to be created for the phy with the zero-address, and other phys
with the zero-address will be tried to be added to the new port:

[562240.051197] sas: ex 500e004aaaaaaa1f phy19:U:0 attached: 0000000000000000 (no device)
// phy19 is deleted but still on the parent port's phy_list
[562240.062536] sas: ex 500e004aaaaaaa1f phy0 new device attached
[562240.062616] sas: ex 500e004aaaaaaa1f phy00:U:5 attached: 0000000000000000 (stp)
[562240.062680] port-7:7:0: trying to add phy phy-7:7:19 fails: it's already part of another port

Therefore, it should be the same as sas_get_phy_attached_dev(). Only when
device_type is SAS_PHY_UNUSED, sas_address is set to the 0 address.

Fixes: 7d1d865 ("[SCSI] libsas: fix false positive 'device attached' conditions")
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Link: https://lore.kernel.org/r/20240312141103.31358-5-yangxingui@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Xingui Yang

drivers/scsi/libsas/sas_expander.c

@@ -261,8 +261,7 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
 	/* help some expanders that fail to zero sas_address in the 'no
 	 * device' case
 	 */
-	if (phy->attached_dev_type == SAS_PHY_UNUSED ||
-	    phy->linkrate < SAS_LINK_RATE_1_5_GBPS)
+	if (phy->attached_dev_type == SAS_PHY_UNUSED)
 		memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
 	else
 		memcpy(phy->attached_sas_addr, dr->attached_sas_addr, SAS_ADDR_SIZE);