From 0b257734344aa89b565bd148ff94f29aa873ffa6 Mon Sep 17 00:00:00 2001 From: "subhashj@codeaurora.org" Date: Wed, 23 Nov 2016 16:33:08 -0800 Subject: [PATCH] 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 Signed-off-by: Subhash Jadavani Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 15 ++++++--------- 1 file 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 -- 2.20.1