Implement SBC START/STOP management. sdev->mange_start_stop is added.
When it's set to one, sd STOPs the device on suspend and shutdown and
STARTs it on resume. sdev->manage_start_stop defaults is in sdev
instead of scsi_disk cdev to allow ->slave_config() override the
default configuration but is exported under scsi_disk sysfs node as
sdev->allow_restart is.
When manage_start_stop is zero (the default value), this patch doesn't
introduce any behavior change.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/scsi_sysfs.c | 31 +++++++++++--
drivers/scsi/sd.c | 102 +++++++++++++++++++++++++++++++++++++++++++++
include/scsi/scsi_device.h | 1
3 files changed, 130 insertions(+), 4 deletions(-)
Index: work/drivers/scsi/sd.c
===================================================================
--- work.orig/drivers/scsi/sd.c
+++ work/drivers/scsi/sd.c
@@ -142,6 +142,8 @@ static void sd_rw_intr(struct scsi_cmnd
static int sd_probe(struct device *);
static int sd_remove(struct device *);
static void sd_shutdown(struct device *dev);
+static int sd_suspend(struct device *dev, pm_message_t state);
+static int sd_resume(struct device *dev);
static void sd_rescan(struct device *);
static int sd_init_command(struct scsi_cmnd *);
static int sd_issue_flush(struct device *, sector_t *);
@@ -206,6 +208,20 @@ static ssize_t sd_store_cache_type(struc
return count;
}
+static ssize_t sd_store_manage_start_stop(struct class_device *cdev,
+ const char *buf, size_t count)
+{
+ struct scsi_disk *sdkp = to_scsi_disk(cdev);
+ struct scsi_device *sdp = sdkp->device;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
+
+ return count;
+}
+
static ssize_t sd_store_allow_restart(struct class_device *cdev, const char *buf,
size_t count)
{
@@ -238,6 +254,14 @@ static ssize_t sd_show_fua(struct class_
return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
}
+static ssize_t sd_show_manage_start_stop(struct class_device *cdev, char *buf)
+{
+ struct scsi_disk *sdkp = to_scsi_disk(cdev);
+ struct scsi_device *sdp = sdkp->device;
+
+ return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
+}
+
static ssize_t sd_show_allow_restart(struct class_device *cdev, char *buf)
{
struct scsi_disk *sdkp = to_scsi_disk(cdev);
@@ -251,6 +275,8 @@ static struct class_device_attribute sd_
__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
sd_store_allow_restart),
+ __ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
+ sd_store_manage_start_stop),
__ATTR_NULL,
};
@@ -267,6 +293,8 @@ static struct scsi_driver sd_template =
.name = "sd",
.probe = sd_probe,
.remove = sd_remove,
+ .suspend = sd_suspend,
+ .resume = sd_resume,
.shutdown = sd_shutdown,
},
.rescan = sd_rescan,
@@ -1776,6 +1804,32 @@ static void scsi_disk_release(struct cla
kfree(sdkp);
}
+static int sd_start_stop_device(struct scsi_device *sdp, int start)
+{
+ unsigned char cmd[6] = { START_STOP }; /* START_VALID */
+ struct scsi_sense_hdr sshdr;
+ int res;
+
+ if (start)
+ cmd[4] |= 1; /* START */
+
+ if (!scsi_device_online(sdp))
+ return -ENODEV;
+
+ res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
+ SD_TIMEOUT, SD_MAX_RETRIES);
+ if (res) {
+ printk(KERN_WARNING "FAILED\n status = %x, message = %02x, "
+ "host = %d, driver = %02x\n ",
+ status_byte(res), msg_byte(res),
+ host_byte(res), driver_byte(res));
+ if (driver_byte(res) & DRIVER_SENSE)
+ scsi_print_sense_hdr("sd", &sshdr);
+ }
+
+ return res;
+}
+
/*
* Send a SYNCHRONIZE CACHE instruction down to the device through
* the normal SCSI command structure. Wait for the command to
@@ -1794,9 +1848,57 @@ static void sd_shutdown(struct device *d
sdkp->disk->disk_name);
sd_sync_cache(sdp);
}
+
+ if (system_state != SYSTEM_RESTART && sdp->manage_start_stop) {
+ printk(KERN_NOTICE "Stopping disk %s: \n",
+ sdkp->disk->disk_name);
+ sd_start_stop_device(sdp, 0);
+ }
+
scsi_disk_put(sdkp);
}
+static int sd_suspend(struct device *dev, pm_message_t mesg)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
+ int ret;
+
+ if (!sdkp)
+ return 0; /* this can happen */
+
+ if (sdkp->WCE) {
+ printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
+ sdkp->disk->disk_name);
+ ret = sd_sync_cache(sdp);
+ if (ret)
+ return ret;
+ }
+
+ if (mesg.event == PM_EVENT_SUSPEND && sdp->manage_start_stop) {
+ printk(KERN_NOTICE "Stopping disk %s: \n",
+ sdkp->disk->disk_name);
+ ret = sd_start_stop_device(sdp, 0);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int sd_resume(struct device *dev)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
+
+ if (!sdp->manage_start_stop)
+ return 0;
+
+ printk(KERN_NOTICE "Starting disk %s: \n", sdkp->disk->disk_name);
+
+ return sd_start_stop_device(sdp, 1);
+}
+
/**
* init_sd - entry point for this driver (both when built in or when
* a module).
Index: work/include/scsi/scsi_device.h
===================================================================
--- work.orig/include/scsi/scsi_device.h
+++ work/include/scsi/scsi_device.h
@@ -119,6 +119,7 @@ struct scsi_device {
unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
unsigned no_start_on_add:1; /* do not issue start on add */
unsigned allow_restart:1; /* issue START_UNIT in error handler */
+ unsigned manage_start_stop:1; /* Let HLD (sd) manage start/stop */
unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
unsigned select_no_atn:1;
unsigned fix_capacity:1; /* READ_CAPACITY is too high by 1 */
Index: work/drivers/scsi/scsi_sysfs.c
===================================================================
--- work.orig/drivers/scsi/scsi_sysfs.c
+++ work/drivers/scsi/scsi_sysfs.c
@@ -278,6 +278,7 @@ static int scsi_bus_match(struct device
static int scsi_bus_suspend(struct device * dev, pm_message_t state)
{
+ struct device_driver *drv = dev->driver;
struct scsi_device *sdev = to_scsi_device(dev);
struct scsi_host_template *sht = sdev->host->hostt;
int err;
@@ -286,23 +287,45 @@ static int scsi_bus_suspend(struct devic
if (err)
return err;
- if (sht->suspend)
+ /* call HLD suspend first */
+ if (drv && drv->suspend) {
+ err = drv->suspend(dev, state);
+ if (err)
+ return err;
+ }
+
+ /* then, call host suspend */
+ if (sht->suspend) {
err = sht->suspend(sdev, state);
+ if (err) {
+ if (drv && drv->resume)
+ drv->resume(dev);
+ return err;
+ }
+ }
- return err;
+ return 0;
}
static int scsi_bus_resume(struct device * dev)
{
+ struct device_driver *drv = dev->driver;
struct scsi_device *sdev = to_scsi_device(dev);
struct scsi_host_template *sht = sdev->host->hostt;
- int err = 0;
+ int err = 0, err2 = 0;
+ /* call host resume first */
if (sht->resume)
err = sht->resume(sdev);
+ /* then, call HLD resume */
+ if (drv && drv->resume)
+ err2 = drv->resume(dev);
+
scsi_device_resume(sdev);
- return err;
+
+ /* favor LLD failure */
+ return err ? err : err2;;
}
struct bus_type scsi_bus_type = {
-
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