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| author |   Marek Szyprowski <m.szyprowski@samsung.com> | 2017-11-30 13:14:51 +0100 |
|---|---|---|
| committer |   Stephen Boyd <sboyd@codeaurora.org> | 2017-12-05 15:20:03 -0800 |
| commit | 588fb54b0cc5be5fd2e12bb04810534ffc3d49cc (patch) | |
| tree | 885aecff1982f9288aa62255777f6c93b8da46be /drivers/clk/clk.c | |
| parent | Linux 4.15-rc1 (diff) | |
| download | linux-dev-588fb54b0cc5be5fd2e12bb04810534ffc3d49cc.tar.xz linux-dev-588fb54b0cc5be5fd2e12bb04810534ffc3d49cc.zip | |
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: Chanwoo Choi <cw00.choi@samsung.com>
Fixes: 9a34b45397e5 ("clk: Add support for runtime PM")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 647d056df88c..8a1860a36c77 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1564,6 +1564,9 @@ static void clk_change_rate(struct clk_core *core) best_parent_rate = core->parent->rate; } + if (clk_pm_runtime_get(core)) + return; + if (core->flags & CLK_SET_RATE_UNGATE) { unsigned long flags; @@ -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 */ if (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, |