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@...>
drivers/clk/rockchip/clk-cpu.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
@@ -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 = 0;
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 = 0;
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;
}