[PATCH 3.19 133/177] clk: samsung: exynos4: Disable ARMCLK down feature on Exynos4210 SoC

From: Greg Kroah-Hartman
Date: Sat May 02 2015 - 16:26:01 EST


3.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>

commit 3a9e9cb65be84d6c64fbe9c69a73c15d59f29454 upstream.

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: Daniel Drake <drake@xxxxxxxxxxxx>
Cc: Tomasz Figa <t.figa@xxxxxxxxxxx>
Cc: Kukjin Kim <kgene@xxxxxxxxxx>
Fixes: 42773b28e71d ("clk: samsung: exynos4: Enable ARMCLK down feature")
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Michael Turquette <mturquette@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/clk/samsung/clk-exynos4.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

--- a/drivers/clk/samsung/clk-exynos4.c
+++ b/drivers/clk/samsung/clk-exynos4.c
@@ -1354,7 +1354,7 @@ static struct samsung_pll_clock exynos4x
VPLL_LOCK, VPLL_CON0, NULL),
};

-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_clo
__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(stru
samsung_clk_register_alias(ctx, exynos4_aliases,
ARRAY_SIZE(exynos4_aliases));

- exynos4_core_down_clock(soc);
+ if (soc == EXYNOS4X12)
+ exynos4x12_core_down_clock();
exynos4_clk_sleep_init();

samsung_clk_of_add_provider(np, ctx);


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