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authorsubhashj@codeaurora.org <subhashj@codeaurora.org>2016-11-24 01:33:08 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2016-11-29 18:06:57 +0100
commit0b257734344aa89b565bd148ff94f29aa873ffa6 (patch)
tree25ae4aacf23e0c3cb81cb3cfdcf9830b99516f6d
parentscsi: ufs: fix condition in which DME command failure msg is printed out (diff)
downloadlinux-0b257734344aa89b565bd148ff94f29aa873ffa6.tar.xz
linux-0b257734344aa89b565bd148ff94f29aa873ffa6.zip
scsi: ufs: optimize system suspend handling
Consider following sequence of events: 1. UFS is runtime suspended, link_state = Hibern8, device_state = sleep 2. System goes into system suspend, ufshcd_system_suspend() brings both link and device to active state and then puts the device in Power_Down state and link in OFF state. 3. System resumes at some later point in time, ufshcd_system_resume() doesn't do anything as UFS state is runtime suspended. Note that link is still on OFF state and device is in Power_Down state. 4. Now system again goes into suspend without any UFS accesses before it. ufshcd_system_suspend() again brings both link and device to active state and then puts the device in Power_Down state and link if OFF state. But it's unnecessary to bring the link & device in active state as both link and device are already in desired low power states. This change fixes this issue by adding proper state checks in ufshcd_system_suspend(). Reviewed-by: Gilad Broner <gbroner@codeaurora.org> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/ufs/ufshcd.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index b82607856607..4b6cc0773681 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6272,16 +6272,13 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
if (!hba || !hba->is_powered)
return 0;
- if (pm_runtime_suspended(hba->dev)) {
- if (hba->rpm_lvl == hba->spm_lvl)
- /*
- * There is possibility that device may still be in
- * active state during the runtime suspend.
- */
- if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
- hba->curr_dev_pwr_mode) && !hba->auto_bkops_enabled)
- goto out;
+ if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
+ hba->curr_dev_pwr_mode) &&
+ (ufs_get_pm_lvl_to_link_pwr_state(hba->spm_lvl) ==
+ hba->uic_link_state))
+ goto out;
+ if (pm_runtime_suspended(hba->dev)) {
/*
* UFS device and/or UFS link low power states during runtime
* suspend seems to be different than what is expected during