[PATCH v2] scsi: hisi_sas: Add slave_destroy interface for v3 hw

[Yihang Li]

WARNING is triggered when executing link reset of remote PHY
and rmmod SAS driver simultaneously. Following is the WARNING log:

WARNING: CPU: 61 PID: 21818 at drivers/base/core.c:1347 __device_links_no_driver+0xb4/0xc0
 Call trace:
  __device_links_no_driver+0xb4/0xc0
  device_links_driver_cleanup+0xb0/0xfc
  __device_release_driver+0x198/0x23c
  device_release_driver+0x38/0x50
  bus_remove_device+0x130/0x140
  device_del+0x184/0x434
  __scsi_remove_device+0x118/0x150
  scsi_remove_target+0x1bc/0x240
  sas_rphy_remove+0x90/0x94
  sas_rphy_delete+0x24/0x3c
  sas_destruct_devices+0x64/0xa0 [libsas]
  sas_revalidate_domain+0xe4/0x150 [libsas]
  process_one_work+0x1e0/0x46c
  worker_thread+0x15c/0x464
  kthread+0x160/0x170
  ret_from_fork+0x10/0x20
 ---[ end trace 71e059eb58f85d4a ]---

During SAS phy up, link->status is set to DL_STATE_AVAILABLE in
device_links_driver_bound, then this setting influences
__device_links_no_driver() before driver rmmod and caused WARNING.

So we add the slave_destroy interface, to make sure link is removed
after flush workque.

Fixes: 16fd4a7c59170 ("scsi: hisi_sas: Add device link between SCSI devices and hisi_hba")
Signed-off-by: Yihang Li <liyihang9@xxxxxxxxxx>
---
Changs to v1:
- Use the latest interface .sdev_destroy
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index fda07b193137..c7430f7c4048 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2977,7 +2977,7 @@ static int sdev_configure_v3_hw(struct scsi_device *sdev,
 		return 0;
 
 	if (!device_link_add(&sdev->sdev_gendev, dev,
-			     DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)) {
+			     DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)) {
 		if (pm_runtime_enabled(dev)) {
 			dev_info(dev, "add device link failed, disable runtime PM for the host\n");
 			pm_runtime_disable(dev);
@@ -2987,6 +2987,15 @@ static int sdev_configure_v3_hw(struct scsi_device *sdev,
 	return 0;
 }
 
+static void hisi_sas_sdev_destroy(struct scsi_device *sdev)
+{
+	struct Scsi_Host *shost = dev_to_shost(&sdev->sdev_gendev);
+	struct hisi_hba *hisi_hba = shost_priv(shost);
+	struct device *dev = hisi_hba->dev;
+
+	device_link_remove(&sdev->sdev_gendev, dev);
+}
+
 static struct attribute *host_v3_hw_attrs[] = {
 	&dev_attr_phy_event_threshold.attr,
 	&dev_attr_intr_conv_v3_hw.attr,
@@ -3401,6 +3410,7 @@ static const struct scsi_host_template sht_v3_hw = {
 	.sg_tablesize		= HISI_SAS_SGE_PAGE_CNT,
 	.sg_prot_tablesize	= HISI_SAS_SGE_PAGE_CNT,
 	.sdev_init		= hisi_sas_sdev_init,
+	.sdev_destroy		= hisi_sas_sdev_destroy,
 	.shost_groups		= host_v3_hw_groups,
 	.sdev_groups		= sdev_groups_v3_hw,
 	.tag_alloc_policy_rr	= true,
-- 
2.33.0