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| author | Oliver Neukum <oliver@neukum.org> | 2012-01-15 00:16:51 +0100 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2012-02-19 08:08:51 -0600 |
| commit | 46a243f72de931aad2632a0f3de3612534212ae9 (patch) | |
| tree | 34a73f00f3785ce9d2d0b96ab594843bf22e6b88 /drivers/scsi/st.c | |
| parent | fea6d607e154cf96ab22254ccb48addfd43d4cb5 (diff) | |
| download | lwn-46a243f72de931aad2632a0f3de3612534212ae9.tar.gz lwn-46a243f72de931aad2632a0f3de3612534212ae9.zip | |
[SCSI] st: implement PM
This implements basic power management for SCSI tapes.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/st.c')
| -rw-r--r-- | drivers/scsi/st.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 9b28f39bac26..9262cdfa4b23 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -1177,6 +1177,7 @@ static int check_tape(struct scsi_tape *STp, struct file *filp) static int st_open(struct inode *inode, struct file *filp) { int i, retval = (-EIO); + int resumed = 0; struct scsi_tape *STp; struct st_partstat *STps; int dev = TAPE_NR(inode); @@ -1211,6 +1212,11 @@ static int st_open(struct inode *inode, struct file *filp) write_unlock(&st_dev_arr_lock); STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0; + if (scsi_autopm_get_device(STp->device) < 0) { + retval = -EIO; + goto err_out; + } + resumed = 1; if (!scsi_block_when_processing_errors(STp->device)) { retval = (-ENXIO); goto err_out; @@ -1258,6 +1264,8 @@ static int st_open(struct inode *inode, struct file *filp) normalize_buffer(STp->buffer); STp->in_use = 0; scsi_tape_put(STp); + if (resumed) + scsi_autopm_put_device(STp->device); mutex_unlock(&st_mutex); return retval; @@ -1391,6 +1399,7 @@ static int st_release(struct inode *inode, struct file *filp) write_lock(&st_dev_arr_lock); STp->in_use = 0; write_unlock(&st_dev_arr_lock); + scsi_autopm_put_device(STp->device); scsi_tape_put(STp); return result; @@ -4154,6 +4163,7 @@ static int st_probe(struct device *dev) if (error) goto out_free_tape; } + scsi_autopm_put_device(SDp); sdev_printk(KERN_NOTICE, SDp, "Attached scsi tape %s\n", tape_name(tpnt)); @@ -4201,6 +4211,7 @@ static int st_remove(struct device *dev) struct scsi_tape *tpnt; int i, j, mode; + scsi_autopm_get_device(SDp); write_lock(&st_dev_arr_lock); for (i = 0; i < st_dev_max; i++) { tpnt = scsi_tapes[i]; |