[PATCH 5/5] scsi: ufs: hwmon, debugfs: Propagate runtime PM resume errors

[Stanley Jhu]

ufs_hwmon_read(), ufs_hwmon_write(), and ufs_debugfs_get_user_access()
ignore the return value of ufshcd_rpm_get_sync():

1. A hwmon sensor access, a debugfs exception-event write, or a debugfs
   TX equalization retrain request runs when W-LUN runtime resume
   fails, when power.runtime_error is set, or when W-LUN runtime PM is
   disabled while suspended.
2. ufshcd_rpm_get_sync() fails with a negative errno while leaving the
   device unresumed.
3. The caller still issues temperature or exception-event query UPIUs,
   or retrains TX equalization, on the suspended target.

Convert all three call sites to ufshcd_rpm_resume_and_get() and release
hba->host_sem before returning the error, ahead of
__acquire(ufs_debugfs) in ufs_debugfs_get_user_access(). This covers
ee_usr_mask_set(), ufs_debugfs_restart_ee(), and ufs_tx_eq_ctrl_write(),
which all use ufs_debugfs_get_user_access().

Fixes: b294ff3e3449 ("scsi: ufs: core: Enable power management for wlun")
Fixes: e88e2d32200a ("scsi: ufs: core: Probe for temperature notification support")
Fixes: adbabdcf0db0 ("scsi: ufs: core: Add support to retrain TX Equalization via debugfs")
Cc: stable@xxxxxxxxxxxxxxx # needs "scsi: ufs: core: Introduce ufshcd_rpm_resume_and_get() helper"
Signed-off-by: Stanley Jhu <stanleyjhu@xxxxxxxxxx>
---
 drivers/ufs/core/ufs-debugfs.c |  8 +++++++-
 drivers/ufs/core/ufs-hwmon.c   | 12 ++++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/ufs/core/ufs-debugfs.c b/drivers/ufs/core/ufs-debugfs.c
index 9f83628f3e2c..44a1a9692324 100644
--- a/drivers/ufs/core/ufs-debugfs.c
+++ b/drivers/ufs/core/ufs-debugfs.c
@@ -70,12 +70,18 @@ token_context_lock(ufs_debugfs);
 static int ufs_debugfs_get_user_access(struct ufs_hba *hba)
 	__cond_acquires(0, ufs_debugfs)
 {
+	int err;
+
 	down(&hba->host_sem);
 	if (!ufshcd_is_user_access_allowed(hba)) {
 		up(&hba->host_sem);
 		return -EBUSY;
 	}
-	ufshcd_rpm_get_sync(hba);
+	err = ufshcd_rpm_resume_and_get(hba);
+	if (err) {
+		up(&hba->host_sem);
+		return err;
+	}
 	__acquire(ufs_debugfs);
 	return 0;
 }
diff --git a/drivers/ufs/core/ufs-hwmon.c b/drivers/ufs/core/ufs-hwmon.c
index aa0b60a0ee8a..2b9673d92573 100644
--- a/drivers/ufs/core/ufs-hwmon.c
+++ b/drivers/ufs/core/ufs-hwmon.c
@@ -61,7 +61,11 @@ static int ufs_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32
 		return -EBUSY;
 	}
 
-	ufshcd_rpm_get_sync(hba);
+	err = ufshcd_rpm_resume_and_get(hba);
+	if (err) {
+		up(&hba->host_sem);
+		return err;
+	}
 
 	switch (attr) {
 	case hwmon_temp_enable:
@@ -113,7 +117,11 @@ static int ufs_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32
 		return -EBUSY;
 	}
 
-	ufshcd_rpm_get_sync(hba);
+	err = ufshcd_rpm_resume_and_get(hba);
+	if (err) {
+		up(&hba->host_sem);
+		return err;
+	}
 
 	if (val == 1)
 		err = ufshcd_update_ee_usr_mask(hba, MASK_EE_URGENT_TEMP, 0);
-- 
2.56.0.307.g5fe7bd680c-goog