linux-kernel - [PATCH] clk: qcom: gdsc: Ensure regulator init state matches GDSC state

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Date:   Fri, 25 Jun 2021 15:54:14 -0700
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Vinod Koul <vkoul@...nel.org>,
        dmitry.baryshkov@...aro.org
Cc:     linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: [PATCH] clk: qcom: gdsc: Ensure regulator init state matches GDSC state

As GDSCs are registered and found to be already enabled
gdsc_toggle_logic() will be invoked for votable GDSCs and ensure that
the vote is matching the hardware state. Part of this the related
regulator will be enabled.

But for non-votable GDSCs the regulator and GDSC status will be out of
sync and as the GDSC is later disabled regulator_disable() will face an
unbalanced enable-count, or something might turn off the supply under
the feet of the GDSC.

So ensure that the regulator is enabled even for non-votable GDSCs.

Cc: stable@...r.kernel.org
Fixes: 37416e554961 ("clk: qcom: gdsc: Handle GDSC regulator supplies")
Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
---
 drivers/clk/qcom/gdsc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index 51ed640e527b..f7e7759cdb90 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -359,10 +359,17 @@ static int gdsc_init(struct gdsc *sc)
 
 	/*
 	 * Votable GDSCs can be ON due to Vote from other masters.
-	 * If a Votable GDSC is ON, make sure we have a Vote.
+	 * If a Votable GDSC is ON, make sure we have a Vote. If
+	 * non-votable, ensure that the supply is kept enabled (as
+	 * is done by gdsc_enable).
 	 */
-	if ((sc->flags & VOTABLE) && on)
+	if ((sc->flags & VOTABLE) && on) {
 		gdsc_enable(&sc->pd);
+	} else if (on) {
+		ret = regulator_enable(sc->rsupply);
+		if (ret < 0)
+			return ret;
+	}
 
 	/*
 	 * Make sure the retain bit is set if the GDSC is already on, otherwise
-- 
2.29.2