[PATCH 2/2] scsi: ufs: core: Dynamically disable timestamp on unsupported devices

[Stanley Jhu]

JEDEC JESD220F specifies that the Timestamp attribute (qTimestamp) is
an optional feature for UFS devices. Some compliant UFS 4.0 devices do
not implement it and return QUERY_RESULT_INVALID_IDN (0xFD).

ufshcd_set_timestamp_attr() gates the write on wspecversion >= 0x400
and the absence of UFS_DEVICE_QUIRK_NO_TIMESTAMP_SUPPORT. Neither
covers a device that advertises UFS 4.0 but declines the attribute, so
the write is reissued on every boot and every resume.

Record the capability in struct ufs_dev_info and clear it when the
device answers -EOPNOTSUPP, so the write is not retried. -ETIMEDOUT
and -EIO still reach dev_err(); they are transient and must not
disable the attribute.

Signed-off-by: Stanley Jhu <stanleyjhu@xxxxxxxxxx>
---
 drivers/ufs/core/ufshcd.c | 10 +++++++---
 include/ufs/ufs.h         |  1 +
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index f01703c3825f..1964d0a23c17 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -8962,6 +8962,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 
 	ufs_fixup_device_setup(hba);
 
+	dev_info->timestamp_sup = dev_info->wspecversion >= 0x400 &&
+		!(hba->dev_quirks & UFS_DEVICE_QUIRK_NO_TIMESTAMP_SUPPORT);
+
 	ufshcd_wb_probe(hba, desc_buf);
 
 	ufshcd_temp_notif_probe(hba, desc_buf);
@@ -9262,14 +9265,15 @@ static void ufshcd_set_timestamp_attr(struct ufs_hba *hba)
 	u64 ts_ns;
 	int err;
 
-	if (dev_info->wspecversion < 0x400 ||
-	    hba->dev_quirks & UFS_DEVICE_QUIRK_NO_TIMESTAMP_SUPPORT)
+	if (!dev_info->timestamp_sup)
 		return;
 
 	ts_ns = ktime_get_real_ns();
 	err = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
 				      QUERY_ATTR_IDN_TIMESTAMP, 0, 0, &ts_ns);
-	if (err)
+	if (err == -EOPNOTSUPP)
+		dev_info->timestamp_sup = false;
+	else if (err)
 		dev_err(hba->dev, "%s: failed to set timestamp %d\n",
 			__func__, err);
 }
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index afbb32654fab..b0207e694911 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -662,6 +662,7 @@ struct ufs_dev_info {
 	u8 rtt_cap; /* bDeviceRTTCap */
 
 	bool hid_sup;
+	bool timestamp_sup;
 
 	/* Unique device ID string (manufacturer+model+serial+version+date) */
 	char *device_id;
-- 
2.55.0.1007.g17ff1f9808-goog