Place the ODD into runtime suspend state as soon as there is nobody
using it. The only exception is, if we just find that a new medium is
inserted, we wait for the next events checking to idle it.
Based on ideas of Alan Stern and Oliver Neukum.
Signed-off-by: Aaron Lu <aaron...@intel.com>
---
drivers/scsi/sr.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 5fc97d2..7a8222f 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -45,6 +45,7 @@
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/pm_runtime.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
@@ -146,8 +147,12 @@ 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 (scsi_autopm_get_device(cd->device))
+ goto out_pm;
goto out;
+ out_pm:
+ scsi_device_put(cd->device);
out_put:
kref_put(&cd->kref, sr_kref_release);
cd = NULL;
@@ -163,6 +168,7 @@ 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);
+ scsi_autopm_put_device(sdev);
mutex_unlock(&sr_ref_mutex);
}
@@ -211,7 +217,7 @@ static unsigned int sr_check_events(struct
cdrom_device_info *cdi,
unsigned int clearing, int slot)
{
struct scsi_cd *cd = cdi->handle;
- bool last_present;
+ bool last_present = cd->media_present;
struct scsi_sense_hdr sshdr;
unsigned int events;
int ret;
@@ -220,6 +226,8 @@ static unsigned int sr_check_events(struct
cdrom_device_info *cdi,
if (CDSL_CURRENT != slot)
return 0;
+ scsi_autopm_get_device(cd->device);
+
events = sr_get_events(cd->device);
cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
@@ -246,10 +254,9 @@ static unsigned int sr_check_events(struct
cdrom_device_info *cdi,
}
if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
- return events;
+ goto out;
do_tur:
/* let's see whether the media is there with TUR */
- last_present = cd->media_present;
ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
/*
@@ -270,7 +277,7 @@ do_tur:
}
if (cd->ignore_get_event)
- return events;
+ goto out;
/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
if (!cd->tur_changed) {
@@ -287,6 +294,12 @@ do_tur:
cd->tur_changed = false;
cd->get_event_changed = false;
+out:
+ if (cd->media_present && !last_present)
+ pm_runtime_put_noidle(&cd->device->sdev_gendev);
+ else
+ scsi_autopm_put_device(cd->device);
+
return events;
}
@@ -715,9 +728,14 @@ static int sr_probe(struct device *dev)
dev_set_drvdata(dev, cd);
disk->flags |= GENHD_FL_REMOVABLE;
add_disk(disk);
+ disk_events_set_poll_msecs(disk, 5000);
sdev_printk(KERN_DEBUG, sdev,
"Attached scsi CD-ROM %s\n", cd->cdi.name);
+
+ /* enable runtime pm */
+ scsi_autopm_put_device(cd->device);
+
return 0;
fail_put:
@@ -965,6 +983,9 @@ static int sr_remove(struct device *dev)
{
struct scsi_cd *cd = dev_get_drvdata(dev);
+ /* disable runtime pm */
+ scsi_autopm_get_device(cd->device);
+
blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
del_gendisk(cd->disk);
--
1.7.12.21.g871e293
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