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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Nicolas Boichat <drinkcat@chromium.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 067/242] soc: mediatek: Check if power domains can be powered on at boot time
Date:   Mon, 28 Dec 2020 13:47:52 +0100
Message-Id: <20201228124907.980113755@linuxfoundation.org>
In-Reply-To: <20201228124904.654293249@linuxfoundation.org>
References: <20201228124904.654293249@linuxfoundation.org>
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From: Nicolas Boichat <drinkcat@chromium.org>

[ Upstream commit 4007844b05815717f522c7ea9914e24ad0ff6c79 ]

In the error case, where a power domain cannot be powered on
successfully at boot time (in mtk_register_power_domains),
pm_genpd_init would still be called with is_off=false, and the
system would later try to disable the power domain again, triggering
warnings as disabled clocks are disabled again (and other potential
issues).

Also print a warning splat in that case, as this should never
happen.

Fixes: c84e358718a66f7 ("soc: Mediatek: Add SCPSYS power domain driver")
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Link: https://lore.kernel.org/r/20200928113107.v2.1.I5e6f8c262031d0451fe7241b744f4f3111c1ce71@changeid
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/soc/mediatek/mtk-scpsys.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index fb2a8b1e79791..d0b18cc7e61b5 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -481,6 +481,7 @@ static void mtk_register_power_domains(struct platform_device *pdev,
 	for (i = 0; i < num; i++) {
 		struct scp_domain *scpd = &scp->domains[i];
 		struct generic_pm_domain *genpd = &scpd->genpd;
+		bool on;
 
 		/*
 		 * Initially turn on all domains to make the domains usable
@@ -488,9 +489,9 @@ static void mtk_register_power_domains(struct platform_device *pdev,
 		 * software.  The unused domains will be switched off during
 		 * late_init time.
 		 */
-		genpd->power_on(genpd);
+		on = !WARN_ON(genpd->power_on(genpd) < 0);
 
-		pm_genpd_init(genpd, NULL, false);
+		pm_genpd_init(genpd, NULL, !on);
 	}
 
 	/*
-- 
2.27.0