linux-kernel - [PATCH] ARM: sunxi: Fix CPU powerdown on A83T

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Date:   Mon, 28 Oct 2019 22:49:14 +0100
From:   Ondrej Jirman <megous@...ous.com>
To:     linux-sunxi@...glegroups.com
Cc:     Ondrej Jirman <megous@...ous.com>, stable@...r.kernel.org,
        Maxime Ripard <mripard@...nel.org>,
        Chen-Yu Tsai <wens@...e.org>,
        Russell King <linux@...linux.org.uk>,
        linux-arm-kernel@...ts.infradead.org (moderated list:ARM/Allwinner
        sunXi SoC support), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] ARM: sunxi: Fix CPU powerdown on A83T

PRCM_PWROFF_GATING_REG has CPU0 at bit 4 on A83T. So without this
patch, instead of gating the CPU0, the whole cluster was power gated,
when shutting down first CPU in the cluster.

Fixes: 6961275e72a8c1 ("ARM: sun8i: smp: Add support for A83T")
Signed-off-by: Ondrej Jirman <megous@...ous.com>
Cc: stable@...r.kernel.org
---
 arch/arm/mach-sunxi/mc_smp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c
index 239084cf8192..26cbce135338 100644
--- a/arch/arm/mach-sunxi/mc_smp.c
+++ b/arch/arm/mach-sunxi/mc_smp.c
@@ -481,14 +481,18 @@ static void sunxi_mc_smp_cpu_die(unsigned int l_cpu)
 static int sunxi_cpu_powerdown(unsigned int cpu, unsigned int cluster)
 {
 	u32 reg;
+	int gating_bit = cpu;
 
 	pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
 	if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
 		return -EINVAL;
 
+	if (is_a83t && cpu == 0)
+		gating_bit = 4;
+
 	/* gate processor power */
 	reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
-	reg |= PRCM_PWROFF_GATING_REG_CORE(cpu);
+	reg |= PRCM_PWROFF_GATING_REG_CORE(gating_bit);
 	writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 	udelay(20);
 
-- 
2.23.0