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>
diff --git a/arch/arm/mach-tegra/common.c b/arch/arm/mach-tegra/common.c
index 34559d1..54826b8 100644
--- a/arch/arm/mach-tegra/common.c
+++ b/arch/arm/mach-tegra/common.c
@@ -39,9 +39,10 @@
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[] = {