Commit a5e1baf7dca10f8cf945394034013260297bc416
Committed by
Michael Turquette
Michael Turquette
1 parent
b71e8ecd57
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
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"]
Showing 1 changed file with 6 additions and 4 deletions Side-by-side Diff
drivers/clk/rockchip/clk-cpu.c
| ... | ... | @@ -124,10 +124,11 @@ |
| 124 | 124 | { |
| 125 | 125 | const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data; |
| 126 | 126 | unsigned long alt_prate, alt_div; |
| 127 | + unsigned long flags; | |
| 127 | 128 | |
| 128 | 129 | alt_prate = clk_get_rate(cpuclk->alt_parent); |
| 129 | 130 | |
| 130 | - spin_lock(cpuclk->lock); | |
| 131 | + spin_lock_irqsave(cpuclk->lock, flags); | |
| 131 | 132 | |
| 132 | 133 | /* |
| 133 | 134 | * If the old parent clock speed is less than the clock speed |
| ... | ... | @@ -164,7 +165,7 @@ |
| 164 | 165 | cpuclk->reg_base + reg_data->core_reg); |
| 165 | 166 | } |
| 166 | 167 | |
| 167 | - spin_unlock(cpuclk->lock); | |
| 168 | + spin_unlock_irqrestore(cpuclk->lock, flags); | |
| 168 | 169 | return 0; |
| 169 | 170 | } |
| 170 | 171 | |
| ... | ... | @@ -173,6 +174,7 @@ |
| 173 | 174 | { |
| 174 | 175 | const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data; |
| 175 | 176 | const struct rockchip_cpuclk_rate_table *rate; |
| 177 | + unsigned long flags; | |
| 176 | 178 | |
| 177 | 179 | rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate); |
| 178 | 180 | if (!rate) { |
| ... | ... | @@ -181,7 +183,7 @@ |
| 181 | 183 | return -EINVAL; |
| 182 | 184 | } |
| 183 | 185 | |
| 184 | - spin_lock(cpuclk->lock); | |
| 186 | + spin_lock_irqsave(cpuclk->lock, flags); | |
| 185 | 187 | |
| 186 | 188 | if (ndata->old_rate < ndata->new_rate) |
| 187 | 189 | rockchip_cpuclk_set_dividers(cpuclk, rate); |
| ... | ... | @@ -201,7 +203,7 @@ |
| 201 | 203 | if (ndata->old_rate > ndata->new_rate) |
| 202 | 204 | rockchip_cpuclk_set_dividers(cpuclk, rate); |
| 203 | 205 | |
| 204 | - spin_unlock(cpuclk->lock); | |
| 206 | + spin_unlock_irqrestore(cpuclk->lock, flags); | |
| 205 | 207 | return 0; |
| 206 | 208 | } |
| 207 | 209 |