In case user's system is broken with ZPODD(either platform or device),
we use this flag to let user disable ZPODD.
A sysfs entry may_power_off is used as the interface to show/store
the scsi device's may_power_off flag.
If 0, we will disable ZPODD; If 1, we will re-enable ZPODD.
The sysfs entry for may_power_off only appears for those ZPODD
capable system(platform + device), and may_power_off implies
can_power_off.
By default, we set may_power_off to 1.
Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
---
drivers/scsi/sr.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 49 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index e6e5549..bc9df62 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -158,7 +158,7 @@ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
kref_get(&cd->kref);
if (scsi_device_get(cd->device))
goto out_put;
- if (cd->device->can_power_off && scsi_autopm_get_device(cd->device))
+ if (scsi_autopm_get_device(cd->device))
goto out_pm;
goto out;
@@ -179,11 +179,50 @@ static void scsi_cd_put(struct scsi_cd *cd)
mutex_lock(&sr_ref_mutex);
kref_put(&cd->kref, sr_kref_release);
scsi_device_put(sdev);
- if (sdev->can_power_off)
- scsi_autopm_put_device_autosuspend(sdev);
+ scsi_autopm_put_device_autosuspend(sdev);
mutex_unlock(&sr_ref_mutex);
}
+static ssize_t
+may_power_off_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ return snprintf(buf, 10, "%d\n", sdev->may_power_off);
+}
+
+static ssize_t
+may_power_off_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int value = -EINVAL;
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct scsi_cd *cd = dev_get_drvdata(dev);
+
+ if (buf[1] == '\0' || (buf[1] == '\n' && buf[2] == '\0')) {
+ if (buf[0] == '1')
+ value = 1;
+ else if (buf[0] == '0')
+ value = 0;
+ }
+
+ if (value >= 0) {
+ if (sdev->may_power_off != value) {
+ if (value == 0) {
+ if (!atomic_dec_and_test(&cd->suspend_count))
+ scsi_autopm_get_device(cd->device);
+ } else
+ atomic_set(&cd->suspend_count, 1);
+ sdev->may_power_off = value;
+ }
+ value = count;
+ }
+
+ return value;
+}
+DEVICE_ATTR(may_power_off, S_IRUGO | S_IWUSR,
+ may_power_off_show, may_power_off_store);
+
static int sr_suspend(struct device *dev, pm_message_t msg)
{
int poweroff;
@@ -342,7 +381,7 @@ static unsigned int sr_check_events(struct cdrom_device_info *cdi,
return 0;
/* if the logical unit just finished loading/unloading, do a TUR */
- if (cd->device->can_power_off && cd->dbml && sr_unit_load_done(cd)) {
+ if (cd->device->may_power_off && cd->dbml && sr_unit_load_done(cd)) {
events = 0;
goto do_tur;
}
@@ -396,7 +435,7 @@ do_tur:
cd->tur_changed = true;
}
- if (cd->device->can_power_off && !cd->media_present) {
+ if (cd->device->may_power_off && !cd->media_present) {
if (cd->cdi.mask & CDC_CLOSE_TRAY)
poweroff = 1;
else
@@ -850,6 +889,8 @@ static int sr_probe(struct device *dev)
pm_runtime_set_autosuspend_delay(dev, 180 * 1000);
pm_runtime_use_autosuspend(dev);
atomic_set(&cd->suspend_count, 1);
+ sdev->may_power_off = 1;
+ device_create_file(dev, &dev_attr_may_power_off);
}
disk->driverfs_dev = &sdev->sdev_gendev;
@@ -1138,10 +1179,12 @@ static int sr_remove(struct device *dev)
struct scsi_cd *cd = dev_get_drvdata(dev);
/* disable runtime pm and possibly resume the device */
- if (cd->device->can_power_off &&
+ if (cd->device->may_power_off &&
!atomic_dec_and_test(&cd->suspend_count))
scsi_autopm_get_device(cd->device);
+ device_remove_file(dev, &dev_attr_may_power_off);
+
blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
del_gendisk(cd->disk);
--
1.7.11.5
--
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