linux-kernel - [PATCH v2 2/6] scsi: ufs: set load before setting voltage in regulators

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1573120078-15547-3-git-send-email-cang@codeaurora.org>
Date:   Thu,  7 Nov 2019 01:47:53 -0800
From:   Can Guo <cang@...eaurora.org>
To:     asutoshd@...eaurora.org, nguyenb@...eaurora.org,
        rnayak@...eaurora.org, linux-scsi@...r.kernel.org,
        kernel-team@...roid.com, saravanak@...gle.com, salyzyn@...gle.com,
        cang@...eaurora.org
Cc:     Alim Akhtar <alim.akhtar@...sung.com>,
        Avri Altman <avri.altman@....com>,
        Pedro Sousa <pedrom.sousa@...opsys.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Stanley Chu <stanley.chu@...iatek.com>,
        Bean Huo <beanhuo@...ron.com>,
        Tomas Winkler <tomas.winkler@...el.com>,
        Venkat Gopalakrishnan <venkatg@...eaurora.org>,
        Subhash Jadavani <subhashj@...eaurora.org>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v2 2/6] scsi: ufs: set load before setting voltage in regulators

From: Asutosh Das <asutoshd@...eaurora.org>

This sequence change is required to avoid dips in voltage
during boot-up.

Apparently, this dip is caused because in the original
sequence, the regulators are initialized in lpm mode.
And then when the load is set to high, and more current
is drawn, than is allowed in lpm, the dip is seen.

Signed-off-by: Asutosh Das <asutoshd@...eaurora.org>
Signed-off-by: Can Guo <cang@...eaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c2de29f..c386c2d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7225,6 +7225,11 @@ static int ufshcd_config_vreg(struct device *dev,
 	name = vreg->name;
 
 	if (regulator_count_voltages(reg) > 0) {
+		uA_load = on ? vreg->max_uA : 0;
+		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
+		if (ret)
+			goto out;
+
 		if (vreg->min_uV && vreg->max_uV) {
 			min_uV = on ? vreg->min_uV : 0;
 			ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
@@ -7235,11 +7240,6 @@ static int ufshcd_config_vreg(struct device *dev,
 				goto out;
 			}
 		}
-
-		uA_load = on ? vreg->max_uA : 0;
-		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
-		if (ret)
-			goto out;
 	}
 out:
 	return ret;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project