Make it possible to test the impact of the UFS error handler on software
that submits SCSI commands to the UFS driver.
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
Documentation/ABI/testing/sysfs-driver-ufs | 10 ++++++
drivers/scsi/ufs/ufshcd.c | 37 ++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index ec3a7149ced5..2a46f91d3f1b 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1534,3 +1534,13 @@ Contact: Avri Altman <avri.altman@xxxxxxx>
Description: In host control mode the host is the originator of map requests.
To avoid flooding the device with map requests, use a simple throttling
mechanism that limits the number of inflight map requests.
+
+What: /sys/class/scsi_host/*/trigger_eh
+Date: October 2021
+Contact: Bart Van Assche <bvanassche@xxxxxxx>
+Description: Writing into this sysfs attribute triggers the UFS error
+ handler. This is useful for testing how the UFS error handler
+ affects SCSI command processing. The supported values are as
+ follows: "1" triggers the error handler without resetting the
+ host controller and "2" starts the error handler and makes it
+ reset the host interface.
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ecfe1f124f8a..30ff93979840 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8144,6 +8144,42 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
}
}
+static ssize_t trigger_eh_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct Scsi_Host *host = class_to_shost(dev);
+ struct ufs_hba *hba = shost_priv(host);
+
+ /*
+ * Using locking would be a better solution. However, this is a debug
+ * attribute so ufshcd_eh_in_progress() should be good enough.
+ */
+ if (ufshcd_eh_in_progress(hba))
+ return -EBUSY;
+
+ if (sysfs_streq(buf, "1")) {
+ hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED_NON_FATAL;
+ hba->saved_err |= UIC_ERROR;
+ } else if (sysfs_streq(buf, "2")) {
+ hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED_FATAL;
+ hba->saved_err |= UIC_ERROR;
+ } else {
+ return -EINVAL;
+ }
+
+ scsi_schedule_eh(hba->host);
+
+ return count;
+}
+
+static DEVICE_ATTR_WO(trigger_eh);
+
+static struct device_attribute *ufshcd_shost_attrs[] = {
+ &dev_attr_trigger_eh,
+ NULL
+};
+
static const struct attribute_group *ufshcd_driver_groups[] = {
&ufs_sysfs_unit_descriptor_group,
&ufs_sysfs_lun_attributes_group,
@@ -8183,6 +8219,7 @@ static struct scsi_host_template ufshcd_driver_template = {
.max_segment_size = PRDT_DATA_BYTE_COUNT_MAX,
.max_host_blocked = 1,
.track_queue_depth = 1,
+ .shost_attrs = ufshcd_shost_attrs,
.sdev_groups = ufshcd_driver_groups,
.dma_boundary = PAGE_SIZE - 1,
.rpm_autosuspend_delay = RPM_AUTOSUSPEND_DELAY_MS,
