releases/4.0.2/clk-samsung-exynos4-disable-armclk-down-feature-on-exynos4210-soc.patch

From 3a9e9cb65be84d6c64fbe9c69a73c15d59f29454 Mon Sep 17 00:00:00 2001
From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Date: Fri, 27 Mar 2015 17:27:10 +0100
Subject: clk: samsung: exynos4: Disable ARMCLK down feature on Exynos4210 SoC

From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

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@endlessm.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Fixes: 42773b28e71d ("clk: samsung: exynos4: Enable ARMCLK down feature")
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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);