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authorHeiko Stübner <heiko@sntech.de>2015-01-16 17:52:44 +0100
committerMichael Turquette <mturquette@linaro.org>2015-01-17 11:22:39 -0800
commita5e1baf7dca10f8cf945394034013260297bc416 (patch)
treef0c356cefcfa6d70d450323b56f46d20f88790c9
parentb71e8ecd57c8aae5b1815782c47b74ffe3efc09a (diff)
downloadlinux-sh-a5e1baf7dca10f8cf945394034013260297bc416.tar.gz
clk: rockchip: fix deadlock possibility in cpuclk
Lockdep reported a possible deadlock between the cpuclk lock and for example the i2c driver. CPU0 CPU1 ---- ---- lock(clk_lock); local_irq_disable(); lock(&(&i2c->lock)->rlock); lock(clk_lock); <Interrupt> lock(&(&i2c->lock)->rlock); *** DEADLOCK *** The generic clock-types of the core ccf already use spin_lock_irqsave when touching clock registers, so do the same for the cpuclk. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Michael Turquette <mturquette@linaro.org> [mturquette@linaro.org: removed initialization of "flags"]
-rw-r--r--drivers/clk/rockchip/clk-cpu.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
index 75c8c45ef728..8539c4fd34cc 100644
--- a/drivers/clk/rockchip/clk-cpu.c
+++ b/drivers/clk/rockchip/clk-cpu.c
@@ -124,10 +124,11 @@ static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
{
const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
unsigned long alt_prate, alt_div;
+ unsigned long flags;
alt_prate = clk_get_rate(cpuclk->alt_parent);
- spin_lock(cpuclk->lock);
+ spin_lock_irqsave(cpuclk->lock, flags);
/*
* If the old parent clock speed is less than the clock speed
@@ -164,7 +165,7 @@ static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
cpuclk->reg_base + reg_data->core_reg);
}
- spin_unlock(cpuclk->lock);
+ spin_unlock_irqrestore(cpuclk->lock, flags);
return 0;
}
@@ -173,6 +174,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
{
const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
const struct rockchip_cpuclk_rate_table *rate;
+ unsigned long flags;
rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
if (!rate) {
@@ -181,7 +183,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
return -EINVAL;
}
- spin_lock(cpuclk->lock);
+ spin_lock_irqsave(cpuclk->lock, flags);
if (ndata->old_rate < ndata->new_rate)
rockchip_cpuclk_set_dividers(cpuclk, rate);
@@ -201,7 +203,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
if (ndata->old_rate > ndata->new_rate)
rockchip_cpuclk_set_dividers(cpuclk, rate);
- spin_unlock(cpuclk->lock);
+ spin_unlock_irqrestore(cpuclk->lock, flags);
return 0;
}