From 588fb54b0cc5be5fd2e12bb04810534ffc3d49cc Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Thu, 30 Nov 2017 13:14:51 +0100 Subject: [PATCH 1/3] 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 Fixes: 9a34b45397e5 ("clk: Add support for runtime PM") Signed-off-by: Marek Szyprowski Reviewed-by: Ulf Hansson Tested-by: Chanwoo Choi Reviewed-by: Chanwoo Choi Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 5 +++++ 1 file changed, 5 insertions(+) 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, From 975b820b6836b6b6c42fb84cd2e772e2b41bca67 Mon Sep 17 00:00:00 2001 From: Cai Li Date: Tue, 21 Nov 2017 17:24:38 +0800 Subject: [PATCH 2/3] clk: fix a panic error caused by accessing NULL pointer In some cases the clock parent would be set NULL when doing re-parent, it will cause a NULL pointer accessing if clk_set trace event is enabled. This patch sets the parent as "none" if the input parameter is NULL. Fixes: dfc202ead312 (clk: Add tracepoints for hardware operations) Signed-off-by: Cai Li Signed-off-by: Chunyan Zhang Signed-off-by: Stephen Boyd --- include/trace/events/clk.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/trace/events/clk.h b/include/trace/events/clk.h index 758607226bfd..2cd449328aee 100644 --- a/include/trace/events/clk.h +++ b/include/trace/events/clk.h @@ -134,12 +134,12 @@ DECLARE_EVENT_CLASS(clk_parent, TP_STRUCT__entry( __string( name, core->name ) - __string( pname, parent->name ) + __string( pname, parent ? parent->name : "none" ) ), TP_fast_assign( __assign_str(name, core->name); - __assign_str(pname, parent->name); + __assign_str(pname, parent ? parent->name : "none"); ), TP_printk("%s %s", __get_str(name), __get_str(pname)) From 61d2f2a05765a5f57149efbd93e3e81a83cbc2c1 Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Mon, 18 Dec 2017 11:57:51 +0800 Subject: [PATCH 3/3] clk: sunxi: sun9i-mmc: Implement reset callback for reset controls Our MMC host driver now issues a reset, instead of just deasserting the reset control, since commit c34eda69ad4c ("mmc: sunxi: Reset the device at probe time"). The sun9i-mmc clock driver does not support this, and will fail, which results in MMC not probing. This patch implements the reset callback by asserting the reset control, then deasserting it after a small delay. Fixes: 7a6fca879f59 ("clk: sunxi: Add driver for A80 MMC config clocks/resets") Cc: # 4.14.x Signed-off-by: Chen-Yu Tsai Acked-by: Philipp Zabel Acked-by: Maxime Ripard Signed-off-by: Michael Turquette Link: lkml.kernel.org/r/20171218035751.20661-1-wens@csie.org --- drivers/clk/sunxi/clk-sun9i-mmc.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/clk/sunxi/clk-sun9i-mmc.c b/drivers/clk/sunxi/clk-sun9i-mmc.c index a1a634253d6f..f00d8758ba24 100644 --- a/drivers/clk/sunxi/clk-sun9i-mmc.c +++ b/drivers/clk/sunxi/clk-sun9i-mmc.c @@ -16,6 +16,7 @@ #include #include +#include #include #include #include @@ -83,9 +84,20 @@ static int sun9i_mmc_reset_deassert(struct reset_controller_dev *rcdev, return 0; } +static int sun9i_mmc_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + sun9i_mmc_reset_assert(rcdev, id); + udelay(10); + sun9i_mmc_reset_deassert(rcdev, id); + + return 0; +} + static const struct reset_control_ops sun9i_mmc_reset_ops = { .assert = sun9i_mmc_reset_assert, .deassert = sun9i_mmc_reset_deassert, + .reset = sun9i_mmc_reset_reset, }; static int sun9i_a80_mmc_config_clk_probe(struct platform_device *pdev)