[PATCH 3.13 40/40] ARM: imx6: Initialize low-power mode early again

From: Greg Kroah-Hartman
Date: Tue Feb 18 2014 - 17:47:53 EST


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

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

From: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>

commit e7c57ecd6019cc6392223605aed18cce257c3eff upstream.

Since commit 9e8147bb5ec5d1dda2141da70f96b98985a306cb
"ARM: imx6q: move low-power code out of clock driver"
the kernel fails to boot on i.MX6Q/D if preemption is
enabled (CONFIG_PREEMPT=y). The kernel just hangs
before the console comes up.

The above commit moved the initalization of the low-power
mode setting (enabling clocked WAIT states), which was
introduced in commit 83ae20981ae924c37d02a42c829155fc3851260c
"ARM: imx: correct low-power mode setting", from
imx6q_clks_init to imx6q_pm_init. Now it is called
much later, after all cores are enabled.

This patch moves the low-power mode initialization back
to imx6q_clks_init again (and to imx6sl_clks_init).

Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm/mach-imx/clk-imx6q.c | 3 +++
arch/arm/mach-imx/clk-imx6sl.c | 3 +++
arch/arm/mach-imx/pm-imx6q.c | 2 --
3 files changed, 6 insertions(+), 2 deletions(-)

--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -479,6 +479,9 @@ static void __init imx6q_clocks_init(str
if (IS_ENABLED(CONFIG_PCI_IMX6))
clk_set_parent(clk[lvds1_sel], clk[sata_ref]);

+ /* Set initial power mode */
+ imx6q_set_lpm(WAIT_CLOCKED);
+
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpt");
base = of_iomap(np, 0);
WARN_ON(!base);
--- a/arch/arm/mach-imx/clk-imx6sl.c
+++ b/arch/arm/mach-imx/clk-imx6sl.c
@@ -261,6 +261,9 @@ static void __init imx6sl_clocks_init(st
clk_prepare_enable(clks[IMX6SL_CLK_USBPHY2_GATE]);
}

+ /* Set initial power mode */
+ imx6q_set_lpm(WAIT_CLOCKED);
+
np = of_find_compatible_node(NULL, NULL, "fsl,imx6sl-gpt");
base = of_iomap(np, 0);
WARN_ON(!base);
--- a/arch/arm/mach-imx/pm-imx6q.c
+++ b/arch/arm/mach-imx/pm-imx6q.c
@@ -228,8 +228,6 @@ void __init imx6q_pm_init(void)
regmap_update_bits(gpr, IOMUXC_GPR1, IMX6Q_GPR1_GINT,
IMX6Q_GPR1_GINT);

- /* Set initial power mode */
- imx6q_set_lpm(WAIT_CLOCKED);

suspend_set_ops(&imx6q_pm_ops);
}


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