[PATCH v6 04/16] ufs: core: Defer adding host to scsi if mcq is supported

[Asutosh Das <quic_asutoshd@xxxxxxxxxxx>]

If MCQ support is present, enabling it after MCQ support
has been configured would require reallocating tags and memory.
It would also free up the already allocated memory in
Single Doorbell Mode. So defer invoking scsi_add_host() until
MCQ is configured.

Co-developed-by: Can Guo <quic_cang@xxxxxxxxxxx>
Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
Signed-off-by: Asutosh Das <quic_asutoshd@xxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 drivers/ufs/core/ufshcd.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index eca15b0..3c2220c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -92,6 +92,11 @@
 /* UFSHC 4.0 compliant HC support this mode, refer param_set_mcq_mode() */
 static bool use_mcq_mode = true;
 
+static bool is_mcq_supported(struct ufs_hba *hba)
+{
+        return hba->mcq_sup && use_mcq_mode;
+}
+
 static int param_set_mcq_mode(const char *val, const struct kernel_param *kp)
 {
 	int ret;
@@ -8227,6 +8232,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
 	int ret;
 	unsigned long flags;
 	ktime_t start = ktime_get();
+	struct Scsi_Host *host = hba->host;
 
 	hba->ufshcd_state = UFSHCD_STATE_RESET;
 
@@ -8261,6 +8267,14 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
 		ret = ufshcd_device_params_init(hba);
 		if (ret)
 			goto out;
+
+		if (is_mcq_supported(hba)) {
+			ret = scsi_add_host(host, hba->dev);
+			if (ret) {
+				dev_err(hba->dev, "scsi_add_host failed\n");
+				goto out;
+			}
+		}
 	}
 
 	ufshcd_tune_unipro_params(hba);
@@ -9857,10 +9871,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 		hba->is_irq_enabled = true;
 	}
 
-	err = scsi_add_host(host, hba->dev);
-	if (err) {
-		dev_err(hba->dev, "scsi_add_host failed\n");
-		goto out_disable;
+	if (!is_mcq_supported(hba)) {
+		err = scsi_add_host(host, hba->dev);
+		if (err) {
+			dev_err(hba->dev, "scsi_add_host failed\n");
+			goto out_disable;
+		}
 	}
 
 	hba->tmf_tag_set = (struct blk_mq_tag_set) {
-- 
2.7.4