From 69d72ac8369a503926b5c494182dd209484de67e Mon Sep 17 00:00:00 2001 From: Subhash Jadavani Date: Thu, 27 Oct 2016 17:26:24 -0700 Subject: [PATCH] scsi: ufs: change device rails hpm mode ramp up sequence When we are resuming the UFS device rails in HPM mode, we are first powering on the VCC rail while VCCQ and VCCQ2 rails still being in LPM mode. Some UFS devices may take VCC on event as hint that host wants UFS device to be resumed and may start drawing more power from the VCCQ/VCCQ2 rails (while they are still in LPM mode) causing voltage drop on these rails. This change fixes this issue by bringing VCCQ & VCCQ2 rails out of LPM before powering on VCC rail. Reviewed-by: Venkat Gopalakrishnan Signed-off-by: Subhash Jadavani Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 9ed96ae942f6..8cf5d8f7683b 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5819,7 +5819,6 @@ static int ufshcd_vreg_set_hpm(struct ufs_hba *hba) !hba->dev_info.is_lu_power_on_wp) { ret = ufshcd_setup_vreg(hba, true); } else if (!ufshcd_is_ufs_dev_active(hba)) { - ret = ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, true); if (!ret && !ufshcd_is_link_active(hba)) { ret = ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq); if (ret) @@ -5828,6 +5827,7 @@ static int ufshcd_vreg_set_hpm(struct ufs_hba *hba) if (ret) goto vccq_lpm; } + ret = ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, true); } goto out; -- 2.11.0