From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Daniel Lezcano <daniel.lezcano@linaro.org>,
        Dmitry Osipenko <digetx@gmail.com>,
        Thierry Reding <treding@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 030/154] cpuidle: tegra: Check whether PMC is ready
Date:   Wed, 24 Nov 2021 12:57:06 +0100
Message-Id: <20211124115703.340414140@linuxfoundation.org>
In-Reply-To: <20211124115702.361983534@linuxfoundation.org>
References: <20211124115702.361983534@linuxfoundation.org>
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From: Dmitry Osipenko <digetx@gmail.com>

[ Upstream commit bdb1ffdad3b73e4d0538098fc02e2ea87a6b27cd ]

Check whether PMC is ready before proceeding with the cpuidle registration.
This fixes racing with the PMC driver probe order, which results in a
disabled deepest CC6 idling state if cpuidle driver is probed before the
PMC.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpuidle/cpuidle-tegra.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
index 29c5e83500d33..e6f96d272d240 100644
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -346,6 +346,9 @@ static void tegra_cpuidle_setup_tegra114_c7_state(void)
 
 static int tegra_cpuidle_probe(struct platform_device *pdev)
 {
+	if (tegra_pmc_get_suspend_mode() == TEGRA_SUSPEND_NOT_READY)
+		return -EPROBE_DEFER;
+
 	/* LP2 could be disabled in device-tree */
 	if (tegra_pmc_get_suspend_mode() < TEGRA_SUSPEND_LP2)
 		tegra_cpuidle_disable_state(TEGRA_CC6);
-- 
2.33.0