scsi: mpi3mr: Fix device loss during enclosure reboot due to zero link speed

During enclosure reboot or expander reset, firmware may report a link
speed of 0 in "Device Add" events while the link is still coming up.
The driver drops such devices, leaving them missing even after the link
recovers.

Fix this by treating link speed 0 as 1.5 Gbps during device addition so
the device is exposed to the OS. The actual link speed will be updated
later when link-up events arrive.

Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Link: https://lore.kernel.org/r/20250820084138.228471-2-chandrakanth.patil@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: cp890582

drivers/scsi/mpi3mr/mpi3mr_os.c

@@ -2049,8 +2049,8 @@ static void mpi3mr_fwevt_bh(struct mpi3mr_ioc *mrioc,
 	if (!fwevt->process_evt)
 		goto evt_ack;
 
-	dprint_event_bh(mrioc, "processing event(0x%02x) in the bottom half handler\n",
-	    fwevt->event_id);
+	dprint_event_bh(mrioc, "processing event(0x%02x) -(0x%08x) in the bottom half handler\n",
+			fwevt->event_id, fwevt->evt_ctx);
 
 	switch (fwevt->event_id) {
 	case MPI3_EVENT_DEVICE_ADDED:
@@ -3076,8 +3076,8 @@ void mpi3mr_os_handle_events(struct mpi3mr_ioc *mrioc,
 	}
 	if (process_evt_bh || ack_req) {
 		dprint_event_th(mrioc,
-			"scheduling bottom half handler for event(0x%02x),ack_required=%d\n",
-			evt_type, ack_req);
+		    "scheduling bottom half handler for event(0x%02x) - (0x%08x), ack_required=%d\n",
+		    evt_type, le32_to_cpu(event_reply->event_context), ack_req);
 		sz = event_reply->event_data_length * 4;
 		fwevt = mpi3mr_alloc_fwevt(sz);
 		if (!fwevt) {

drivers/scsi/mpi3mr/mpi3mr_transport.c

@@ -413,9 +413,11 @@ static void mpi3mr_remove_device_by_sas_address(struct mpi3mr_ioc *mrioc,
 			 sas_address, hba_port);
 	if (tgtdev) {
 		if (!list_empty(&tgtdev->list)) {
-			list_del_init(&tgtdev->list);
 			was_on_tgtdev_list = 1;
-			mpi3mr_tgtdev_put(tgtdev);
+			if (tgtdev->state == MPI3MR_DEV_REMOVE_HS_STARTED) {
+				list_del_init(&tgtdev->list);
+				mpi3mr_tgtdev_put(tgtdev);
+			}
 		}
 	}
 	spin_unlock_irqrestore(&mrioc->tgtdev_lock, flags);
@@ -2079,6 +2081,8 @@ int mpi3mr_expander_add(struct mpi3mr_ioc *mrioc, u16 handle)
 				link_rate = (expander_pg1.negotiated_link_rate &
 				    MPI3_SAS_NEG_LINK_RATE_LOGICAL_MASK) >>
 				    MPI3_SAS_NEG_LINK_RATE_LOGICAL_SHIFT;
+				if (link_rate < MPI3_SAS_NEG_LINK_RATE_1_5)
+					link_rate = MPI3_SAS_NEG_LINK_RATE_1_5;
 				mpi3mr_update_links(mrioc, sas_address_parent,
 				    handle, i, link_rate, hba_port);
 			}
@@ -2388,6 +2392,9 @@ int mpi3mr_report_tgtdev_to_sas_transport(struct mpi3mr_ioc *mrioc,
 
 	link_rate = mpi3mr_get_sas_negotiated_logical_linkrate(mrioc, tgtdev);
 
+	if (link_rate < MPI3_SAS_NEG_LINK_RATE_1_5)
+		link_rate = MPI3_SAS_NEG_LINK_RATE_1_5;
+
 	mpi3mr_update_links(mrioc, sas_address_parent, tgtdev->dev_handle,
 	    parent_phy_number, link_rate, hba_port);