Hello.
On 21-12-2012 8:35, Derek Basehore wrote:
We no longer wait for the disk to spin up in sd_resume. It now enters the
request to spinup the disk into the elevator and returns.
A function is scheduled under the scsi_sd_probe_domain to wait for the command
to spinup the disk to complete. This function then checks for errors and cleans
up after the sd resume function.
This allows system resume to complete much faster on systems with an HDD since
spinning up the disk is a significant portion of resume time.
Signed-off-by: Derek Basehore <dbasehore@xxxxxxxxxxxx>
---
drivers/scsi/sd.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++---
drivers/scsi/sd.h | 9 ++++
2 files changed, 108 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 7992635..2fe051f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
[...]
@@ -3087,20 +3089,110 @@ done:
return ret;
}
+/*
+ * Callback function for when the request that starts the disk completes. Passed
+ * into blk_execute_rq_nowait in sd_resume.
+ */
+static void sd_end_start_rq(struct request *rq, int error)
+{
+ struct completion *waiting = rq->end_io_data;
+
+ rq->end_io_data = NULL;
+ /*
+ * Set the end_io_data to NULL before calling complete. This (with
+ * sd_resume async) ensures that it is set to NULL before we call
+ * blk_put_request.
+ */
Shouldn't this comment precede the previous statement?
+ complete(waiting);
+}
[...]
static int sd_resume(struct device *dev)
{
struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
- int ret = 0;
+ struct scsi_device *sdp = sdkp->device;
+ struct resume_async_struct *resume = NULL;
+ struct request *req;
+ unsigned char cmd[6] = { START_STOP }; /* START_VALID */
- if (!sdkp->device->manage_start_stop)
- goto done;
+ if (!sdkp->device->manage_start_stop) {
+ scsi_disk_put(sdkp);
+ return 0;
+ }
sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
- ret = sd_start_stop_device(sdkp, 1);
-done:
- scsi_disk_put(sdkp);
- return ret;
+ cmd[4] |= 1; /* START */
+
+ if (sdp->start_stop_pwr_cond)
+ cmd[4] |= 1 << 4; /* Active */
+
+ if (!scsi_device_online(sdp))
+ return -ENODEV;
+
+ resume = kzalloc(sizeof(struct resume_async_struct), GFP_NOIO);
+ if (!resume)
+ return DRIVER_ERROR << 24;
+
+ req = blk_get_request(sdp->request_queue, 0, __GFP_WAIT);
+ if (!req)
+ return DRIVER_ERROR << 24;
+
+ resume->req = req;
+ resume->sdkp = sdkp;
+ init_completion(&resume->wait);
+
+ req->cmd_len = COMMAND_SIZE(cmd[0]);
+ memcpy(req->cmd, cmd, req->cmd_len);
+ req->sense = resume->sense;
+ req->sense_len = 0;
Not SCSI_SENSE_BUFFERSIZE?
+ req->retries = SD_MAX_RETRIES;
+ req->timeout = SD_TIMEOUT;
+ req->cmd_type = REQ_TYPE_BLOCK_PC;
+ req->cmd_flags |= REQ_QUIET | REQ_PREEMPT;
+ req->end_io_data = &resume->wait;
+
+ async_schedule_domain(sd_resume_async, resume, &scsi_sd_probe_domain);
+ /*
+ * don't wait here for the disk to spin up, since we can resume faster
+ * if we don't. Cleanup and checking for errors is done the the
s/the the/in the/
WBR, Sergei
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