From c6b82e8bca9a579ddf894efa69c222f2c373309c Mon Sep 17 00:00:00 2001 From: Sujit Reddy Thumma Date: Fri, 6 Dec 2013 19:02:57 +0530 Subject: [PATCH] scsi: Allow auto suspend override by low-level driver Until now the scsi mid-layer forbids runtime suspend till userspace enables it. This is mainly to quarantine some disks with broken runtime power management or have high latencies executing suspend resume callbacks. If the userspace doesn't enable the runtime suspend the underlying hardware will be always on even when it is not doing any useful work and thus wasting power. Some low-level drivers for the controllers can efficiently use runtime power management to reduce power consumption and improve battery life. Allow runtime suspend parameters override within the LLD itself instead of waiting for userspace to control the power management. Change-Id: I03e96a89d19c174deeb5bd4f94136c77073eb009 Signed-off-by: Sujit Reddy Thumma [subhashj@codeaurora.org: resolved trivial merge conflicts] Signed-off-by: Subhash Jadavani --- drivers/scsi/scsi_scan.c | 4 ++++ drivers/scsi/scsi_sysfs.c | 3 ++- drivers/scsi/sd.c | 3 +++ include/scsi/scsi_device.h | 4 ++++ 4 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 054923e3393c..32060a418a62 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -970,6 +970,10 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, transport_configure_device(&sdev->sdev_gendev); + /* The LLD can override auto suspend tunables in ->slave_configure() */ + sdev->use_rpm_auto = 0; + sdev->autosuspend_delay = SCSI_DEFAULT_AUTOSUSPEND_DELAY; + if (sdev->host->hostt->slave_configure) { ret = sdev->host->hostt->slave_configure(sdev); if (ret) { diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 21930c9ac9cd..e79c2489dd11 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1044,7 +1044,8 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) device_enable_async_suspend(&sdev->sdev_gendev); scsi_autopm_get_target(starget); pm_runtime_set_active(&sdev->sdev_gendev); - pm_runtime_forbid(&sdev->sdev_gendev); + if (!sdev->use_rpm_auto) + pm_runtime_forbid(&sdev->sdev_gendev); pm_runtime_enable(&sdev->sdev_gendev); scsi_autopm_put_target(starget); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index aa64e7de3525..79cef194b9a1 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3049,6 +3049,9 @@ static void sd_probe_async(void *data, async_cookie_t cookie) } blk_pm_runtime_init(sdp->request_queue, dev); + if (sdp->autosuspend_delay >= 0) + pm_runtime_set_autosuspend_delay(dev, sdp->autosuspend_delay); + add_disk(gd); if (sdkp->capacity) sd_dif_config_host(sdkp); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index fe89d7cd67b9..f9f445be1a50 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -175,6 +175,10 @@ struct scsi_device { unsigned no_dif:1; /* T10 PI (DIF) should be disabled */ unsigned broken_fua:1; /* Don't set FUA bit */ unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */ + unsigned use_rpm_auto:1; /* Enable runtime PM auto suspend */ + +#define SCSI_DEFAULT_AUTOSUSPEND_DELAY -1 + int autosuspend_delay; atomic_t disk_events_disable_depth; /* disable depth for disk events */