[PATCH] clk: samsung: exynos4: Disable ARMCLK down feature on Exynos4210 SoC

Bartlomiej Zolnierkiewicz b.zolnierkie at samsung.com
Fri Mar 27 09:27:10 PDT 2015

Commit 42773b28e71d ("clk: samsung: exynos4: Enable ARMCLK
down feature") enabled ARMCLK down feature on all Exynos4
SoCs.  Unfortunately on Exynos4210 SoC ARMCLK down feature
causes a lockup when ondemand cpufreq governor is used.
Fix it by limiting ARMCLK down feature to Exynos4x12 SoCs.

This patch was tested on:
- Exynos4210 SoC based Trats board
- Exynos4210 SoC based Origen board
- Exynos4412 SoC based Trats2 board
- Exynos4412 SoC based Odroid-U3 board

Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Cc: Daniel Drake <drake at endlessm.com>
Cc: Tomasz Figa <t.figa at samsung.com>
Cc: Kukjin Kim <kgene at kernel.org>
Fixes: 42773b28e71d ("clk: samsung: exynos4: Enable ARMCLK down feature")
Cc: <stable at vger.kernel.org> # v3.17+
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
 drivers/clk/samsung/clk-exynos4.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c
index 51462e8..714d6ba 100644
--- a/drivers/clk/samsung/clk-exynos4.c
+++ b/drivers/clk/samsung/clk-exynos4.c
@@ -1354,7 +1354,7 @@ static struct samsung_pll_clock exynos4x12_plls[nr_plls] __initdata = {
-static void __init exynos4_core_down_clock(enum exynos4_soc soc)
+static void __init exynos4x12_core_down_clock(void)
 	unsigned int tmp;
@@ -1373,11 +1373,9 @@ static void __init exynos4_core_down_clock(enum exynos4_soc soc)
 	__raw_writel(tmp, reg_base + PWR_CTRL1);
-	 * Disable the clock up feature on Exynos4x12, in case it was
-	 * enabled by bootloader.
+	 * Disable the clock up feature in case it was enabled by bootloader.
-	if (exynos4_soc == EXYNOS4X12)
-		__raw_writel(0x0, reg_base + E4X12_PWR_CTRL2);
+	__raw_writel(0x0, reg_base + E4X12_PWR_CTRL2);
 /* register exynos4 clocks */
@@ -1474,7 +1472,8 @@ static void __init exynos4_clk_init(struct device_node *np,
 	samsung_clk_register_alias(ctx, exynos4_aliases,
-	exynos4_core_down_clock(soc);
+	if (soc == EXYNOS4X12)
+		exynos4x12_core_down_clock();
 	samsung_clk_of_add_provider(np, ctx);

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