[RFC PATCH 05/13] scsi: ufs: ufshpb: Disable HPB if no HPB-enabled luns

[Avri Altman <avri.altman@wdc.com>]

We are disabling the feature altogether if reading the configuration
fails, or there are no HPB-luns configured, or no active regions are
configure.  Still, after reading the configuration successfully, there
can be no HBP-enabled luns, e.g. if their pinned regions allocation has
failed.

So to avoid keep checking the upiu responses for nothing, we are
verifying that indeed there are any HPB-enabled luns out there after
1min from the configuration read.  By then all the luns were scanned and
initialized their device handler.  If there are no HPB-enabled luns –
the feature is disabled altogether.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufshcd.h |  1 +
 drivers/scsi/ufs/ufshpb.c | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index e7014a3..19a5613 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -743,6 +743,7 @@ struct ufs_hba {
 	struct request_queue	*bsg_queue;
 	bool wb_buf_flush_enabled;
 	bool wb_enabled;
+	struct delayed_work hpb_disable_work;
 };
 
 /* Returns true if clocks can be gated. Otherwise false */
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 4a10e7b..be926cb 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -299,6 +299,28 @@ static int ufshpb_get_unit_config(struct ufs_hba *hba, u8 dev_num_luns)
 	return ret;
 }
 
+static void ufshpb_disable_work(struct work_struct *work)
+{
+	struct ufs_hba *hba = container_of(work, struct ufs_hba,
+					   hpb_disable_work.work);
+
+	if (ufshpb_luns) {
+		unsigned int num_hpb_luns = ufshpb_conf->num_hpb_luns;
+		int i;
+
+		for (i = 0; i < num_hpb_luns; i++) {
+			struct ufshpb_lun *hpb = ufshpb_luns + i;
+
+			if (hpb->sdev && hpb->sdev->handler_data)
+				return;
+		}
+	}
+
+	hba->caps &= ~UFSHCD_CAP_HPB;
+	ufshpb_remove(hba);
+	dev_info(hba->dev, "HPB was removed - no active HPB luns\n");
+}
+
 /**
  * ufshpb_probe - read hpb config from the device
  * @hba: per adapter object
@@ -368,6 +390,8 @@ int ufshpb_probe(struct ufs_hba *hba)
 	if (ret)
 		goto out;
 
+	INIT_DELAYED_WORK(&hba->hpb_disable_work, ufshpb_disable_work);
+	schedule_delayed_work(&hba->hpb_disable_work, 60 * HZ);
 out:
 	kfree(dev_desc);
 	if (ret) {
-- 
2.7.4