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>
parent
f37e9f8c
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