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authorMarek Szyprowski <m.szyprowski@samsung.com>2017-11-30 13:14:51 +0100
committerStephen Boyd <sboyd@codeaurora.org>2017-12-06 00:20:03 +0100
commit588fb54b0cc5be5fd2e12bb04810534ffc3d49cc (patch)
tree885aecff1982f9288aa62255777f6c93b8da46be /drivers/clk/clk.c
parentLinux 4.15-rc1 (diff)
downloadlinux-588fb54b0cc5be5fd2e12bb04810534ffc3d49cc.tar.xz
linux-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.c5
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,