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authorSimon Glass <sjg@chromium.org>2011-02-17 17:13:57 +0100
committerColin Cross <ccross@android.com>2011-02-21 05:04:16 +0100
commit375b19cd34ea9b1ab338deac20b4bd2c553bf57b (patch)
tree3840e91e77936f0620afe76925a98d1c1bcefa92
parentARM: tegra: APB DMA: Enable clock and remove reset. (diff)
downloadlinux-375b19cd34ea9b1ab338deac20b4bd2c553bf57b.tar.xz
linux-375b19cd34ea9b1ab338deac20b4bd2c553bf57b.zip
ARM: tegra: Fix hang on reboot
This seems to be a regression in 2.6.37. We cannot use writel() here since the resulting wmb() calls l2x0_cache_sync() which uses a spinlock and L1 cache may be off at this point. http://lists.infradead.org/pipermail/linux-arm-kernel/2011-February/041909.html Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Colin Cross <ccross@android.com>
-rw-r--r--arch/arm/mach-tegra/common.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/common.c b/arch/arm/mach-tegra/common.c
index 34559d157827..54826b805b91 100644
--- a/arch/arm/mach-tegra/common.c
+++ b/arch/arm/mach-tegra/common.c
@@ -39,9 +39,10 @@ void tegra_assert_system_reset(char mode, const char *cmd)
void __iomem *reset = IO_ADDRESS(TEGRA_CLK_RESET_BASE + 0x04);
u32 reg;
- reg = readl(reset);
+ /* use *_related to avoid spinlock since caches are off */
+ reg = readl_relaxed(reset);
reg |= 0x04;
- writel(reg, reset);
+ writel_relaxed(reg, reset);
}
static __initdata struct tegra_clk_init_table common_clk_init_table[] = {