Commit 588fb54b authored by Marek Szyprowski's avatar Marek Szyprowski Committed by Stephen Boyd

clk: Manage proper runtime PM state in clk_change_rate()

clk_change_rate() propagates rate change down to all its children. Such
operation requires managing proper runtime PM state of each child, what
was missing. Add needed calls to clk_pm_runtime*() to ensure that
set_rate() clock callback is called on runtime active clock.

This fixes following issue found on Exynos5433 TM2 board with devfreq
enabled:

Synchronous External Abort: synchronous external abort (0x96000210) at 0xffffff80093f5600
Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5 Comm: kworker/u16:0 Not tainted 4.15.0-rc1-next-20171129+ #4
Hardware name: Samsung TM2 board (DT)
Workqueue: devfreq_wq devfreq_monitor
task: ffffffc0ca96b600 task.stack: ffffff80093a8000
pstate: a0000085 (NzCv daIf -PAN -UAO)
pc : clk_divider_set_rate+0x54/0x118
lr : clk_divider_set_rate+0x44/0x118
...
Process kworker/u16:0 (pid: 5, stack limit = 0xffffff80093a8000)
Call trace:
 clk_divider_set_rate+0x54/0x118
 clk_change_rate+0xfc/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_change_rate+0x1f0/0x4e0
 clk_core_set_rate_nolock+0x138/0x148
 clk_set_rate+0x28/0x50
 exynos_bus_passive_target+0x6c/0x11c
 update_devfreq_passive+0x58/0xb4
 devfreq_passive_notifier_call+0x50/0x5c
 notifier_call_chain+0x4c/0x88
 __srcu_notifier_call_chain+0x54/0x80
 srcu_notifier_call_chain+0x14/0x1c
 update_devfreq+0x100/0x1b4
 devfreq_monitor+0x2c/0x88
 process_one_work+0x148/0x3d8
 worker_thread+0x13c/0x3f8
 kthread+0x100/0x12c
 ret_from_fork+0x10/0x18
Reported-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Fixes: 9a34b453 ("clk: Add support for runtime PM")
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 4fbd8d19
...@@ -1564,6 +1564,9 @@ static void clk_change_rate(struct clk_core *core) ...@@ -1564,6 +1564,9 @@ static void clk_change_rate(struct clk_core *core)
best_parent_rate = core->parent->rate; best_parent_rate = core->parent->rate;
} }
if (clk_pm_runtime_get(core))
return;
if (core->flags & CLK_SET_RATE_UNGATE) { if (core->flags & CLK_SET_RATE_UNGATE) {
unsigned long flags; unsigned long flags;
...@@ -1634,6 +1637,8 @@ static void clk_change_rate(struct clk_core *core) ...@@ -1634,6 +1637,8 @@ static void clk_change_rate(struct clk_core *core)
/* handle the new child who might not be in core->children yet */ /* handle the new child who might not be in core->children yet */
if (core->new_child) if (core->new_child)
clk_change_rate(core->new_child); clk_change_rate(core->new_child);
clk_pm_runtime_put(core);
} }
static int clk_core_set_rate_nolock(struct clk_core *core, static int clk_core_set_rate_nolock(struct clk_core *core,
......
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