[PATCH 4.14 02/65] clk: Dont try to enable critical clocks if prepare failed

Greg Kroah-Hartman
2020-01-22T09:38:04Z

From: Guenter Roeck <linux@roeck-us.net>

commit 12ead77432f2ce32dea797742316d15c5800cb32 upstream.

The following traceback is seen if a critical clock fails to prepare.

bcm2835-clk 3f101000.cprman: plld: couldn't lock PLL
------------[ cut here ]------------
Enabling unprepared plld_per
WARNING: CPU: 1 PID: 1 at drivers/clk/clk.c:1014 clk_core_enable+0xcc/0x2c0
...
Call trace:
clk_core_enable+0xcc/0x2c0
__clk_register+0x5c4/0x788
devm_clk_hw_register+0x4c/0xb0
bcm2835_register_pll_divider+0xc0/0x150
bcm2835_clk_probe+0x134/0x1e8
platform_drv_probe+0x50/0xa0
really_probe+0xd4/0x308
driver_probe_device+0x54/0xe8
device_driver_attach+0x6c/0x78
__driver_attach+0x54/0xd8
...

Check return values from clk_core_prepare() and clk_core_enable() and
bail out if any of those functions returns an error.

Cc: Jerome Brunet <jbrunet@baylibre.com>
Fixes: 99652a469df1 ("clk: migrate the count of orphaned clocks at init")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lkml.kernel.org/r/20191225163429.29694-1-linux@roeck-us.net
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/clk/clk.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2482,11 +2482,17 @@ static int __clk_core_init(struct clk_co
if (core->flags & CLK_IS_CRITICAL) {
unsigned long flags;

- clk_core_prepare(core);
+ ret = clk_core_prepare(core);
+ if (ret)
+ goto out;

flags = clk_enable_lock();
- clk_core_enable(core);
+ ret = clk_core_enable(core);
clk_enable_unlock(flags);
+ if (ret) {
+ clk_core_unprepare(core);
+ goto out;
+ }
}

/*