On Thu, 29 Sep 2005, Jeff Garzik wrote:
> Joshua Kwan wrote:
> > Hello,
> >
> > I had some time yesterday and decided to help Jens out by rediffing the
> > now-infamous SATA suspend-to-ram patch [1] against current git and
> > test-building it.
> >
> > For posterity,
> >
> > This patch adds the ata_scsi_device_resume and ata_scsi_device_suspend
> > functions (along with helpers) to put to sleep and wake up Serial ATA
> > controllers when entering sleep states, and hooks the functions into
> > each SATA controller driver so that suspend-to-RAM is possible.
> >
> > Note that this patch is a holdover patch until it is possible to
> > generalize this concept for all SCSI devices, which requires more data
> > on which devices need to be put to sleep and which don't.
> >
> > Signed-off-by: Joshua Kwan <[email protected]>
>
> Ah hah! I found the other SCSI suspend patch:
>
> http://lwn.net/Articles/97453/
>
> Anybody (Joshua?) up for reconciling and testing the two?
>
> The main change from Jens/Joshua's patch is that we use SCSI's
> sd_shutdown() to call sync cache, eliminating the need for
> ata_flush_cache(), since the SCSI layer would now perform that.
>
> For bonus points,
>
> 1) sd should call START STOP UNIT on suspend, which eliminates the need
> for ata_standby_drive(), and completely encompasses the suspend process
> in the SCSI layer.
>
> 2) sd should call START STOP UNIT on resume -- and as a SUPER BONUS, the
> combination of these two changes ensures that there are no queue
> synchronization issues, the likes of which would require hacks like
> Jens' while-loop patch.
>
> None of these are huge changes requiring a lot of thinking/planning...
>
> Finally, ideally, we should be issuing a hardware or software reset on
> suspend.
Here's Nathan Bryant's patch (from the lwn.ne article) updated
to 2.6.14-rc2-git7 + changes that Christoph suggested (except
that 'scsi_device_resume' name was already used, so I changed it
to 'scsi_device_wakeup' instead).
I'll get back to Jeff's suggestion(s) and the sysfs flag next,
but others can use this as a basis if wanted.
(also available from
http://www.xenotime.net/linux/scsi/scsi-suspend-resume.patch
)
--
~Randy
drivers/scsi/scsi_priv.h | 2 +
drivers/scsi/scsi_sysfs.c | 39 +++++++++++++++++++++++++++++++++--
drivers/scsi/sd.c | 18 +++++++++++++++-
include/scsi/scsi_driver.h | 2 +
4 files changed, 58 insertions(+), 3 deletions(-)
diff -Naurp -X linux-2614-rc2/Documentation/dontdiff linux-2614-rc2-git7-clean/drivers/scsi/scsi_priv.h linux-2614-rc2-git7-scsi/drivers/scsi/scsi_priv.h
--- linux-2614-rc2-git7-clean/drivers/scsi/scsi_priv.h 2005-09-29 12:58:21.000000000 -0700
+++ linux-2614-rc2-git7-scsi/drivers/scsi/scsi_priv.h 2005-09-29 12:48:00.000000000 -0700
@@ -55,6 +55,8 @@ static inline void scsi_log_send(struct
static inline void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{ };
#endif
+extern int scsi_device_suspend(struct device *dev, pm_message_t state);
+extern int scsi_device_wakeup(struct device *dev);
/* scsi_devinfo.c */
extern int scsi_get_device_flags(struct scsi_device *sdev,
diff -Naurp -X linux-2614-rc2/Documentation/dontdiff linux-2614-rc2-git7-clean/drivers/scsi/scsi_sysfs.c linux-2614-rc2-git7-scsi/drivers/scsi/scsi_sysfs.c
--- linux-2614-rc2-git7-clean/drivers/scsi/scsi_sysfs.c 2005-09-29 12:58:25.000000000 -0700
+++ linux-2614-rc2-git7-scsi/drivers/scsi/scsi_sysfs.c 2005-09-29 12:56:16.000000000 -0700
@@ -14,6 +14,7 @@
#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
@@ -264,8 +265,10 @@ static int scsi_bus_match(struct device
}
struct bus_type scsi_bus_type = {
- .name = "scsi",
- .match = scsi_bus_match,
+ .name = "scsi",
+ .match = scsi_bus_match,
+ .suspend = scsi_device_suspend,
+ .resume = scsi_device_wakeup,
};
int scsi_sysfs_register(void)
@@ -770,6 +773,38 @@ void scsi_remove_target(struct device *d
}
EXPORT_SYMBOL(scsi_remove_target);
+int scsi_device_suspend(struct device *dev, pm_message_t state)
+{
+ int err;
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct scsi_driver *drv = to_scsi_driver(dev->driver);
+
+ err = scsi_device_quiesce(sdev);
+ if (err)
+ return err;
+
+ if (drv->suspend)
+ return drv->suspend(dev, state);
+
+ return 0;
+}
+
+int scsi_device_wakeup(struct device *dev)
+{
+ int err;
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct scsi_driver *drv = to_scsi_driver(dev->driver);
+
+ if (drv->resume) {
+ err = drv->resume(dev);
+ if (err)
+ return err;
+ }
+
+ scsi_device_resume(sdev);
+ return 0;
+}
+
int scsi_register_driver(struct device_driver *drv)
{
drv->bus = &scsi_bus_type;
diff -Naurp -X linux-2614-rc2/Documentation/dontdiff linux-2614-rc2-git7-clean/drivers/scsi/sd.c linux-2614-rc2-git7-scsi/drivers/scsi/sd.c
--- linux-2614-rc2-git7-clean/drivers/scsi/sd.c 2005-09-29 12:58:25.000000000 -0700
+++ linux-2614-rc2-git7-scsi/drivers/scsi/sd.c 2005-09-29 13:02:10.000000000 -0700
@@ -117,6 +117,8 @@ static void sd_rw_intr(struct scsi_cmnd
static int sd_probe(struct device *);
static int sd_remove(struct device *);
+static int sd_suspend(struct device *, pm_message_t);
+static int sd_resume(struct device *);
static void sd_shutdown(struct device *dev);
static void sd_rescan(struct device *);
static int sd_init_command(struct scsi_cmnd *);
@@ -136,6 +138,8 @@ static struct scsi_driver sd_template =
},
.rescan = sd_rescan,
.init_command = sd_init_command,
+ .suspend = sd_suspend,
+ .resume = sd_resume,
.issue_flush = sd_issue_flush,
.prepare_flush = sd_prepare_flush,
.end_flush = sd_end_flush,
@@ -1691,7 +1695,19 @@ static void sd_shutdown(struct device *d
printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
sdkp->disk->disk_name);
sd_sync_cache(sdp);
-}
+}
+
+static int sd_suspend(struct device *dev, pm_message_t state)
+{
+ sd_shutdown(dev);
+ return 0;
+}
+
+static int sd_resume(struct device *dev)
+{
+ sd_rescan(dev);
+ return 0;
+}
/**
* init_sd - entry point for this driver (both when built in or when
diff -Naurp -X linux-2614-rc2/Documentation/dontdiff linux-2614-rc2-git7-clean/include/scsi/scsi_driver.h linux-2614-rc2-git7-scsi/include/scsi/scsi_driver.h
--- linux-2614-rc2-git7-clean/include/scsi/scsi_driver.h 2005-08-28 16:41:01.000000000 -0700
+++ linux-2614-rc2-git7-scsi/include/scsi/scsi_driver.h 2005-09-29 12:47:43.000000000 -0700
@@ -13,6 +13,8 @@ struct scsi_driver {
int (*init_command)(struct scsi_cmnd *);
void (*rescan)(struct device *);
+ int (*suspend)(struct device *dev, pm_message_t state);
+ int (*resume)(struct device *dev);
int (*issue_flush)(struct device *, sector_t *);
int (*prepare_flush)(struct request_queue *, struct request *);
void (*end_flush)(struct request_queue *, struct request *);
-
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