release/5.2.37/clk-Don-t-try-to-enable-critical-clocks-if-prepare-f.patch

From 5298cf62fdc90844b1c7c7c67e7948053cf481fe Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Wed, 25 Dec 2019 08:34:29 -0800
Subject: [PATCH] clk: Don't try to enable critical clocks if prepare failed

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: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 49c942e4ffa0..2c5a21a96935 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3364,11 +3364,17 @@ static int __clk_core_init(struct clk_core *core)
 	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;
+		}
 	}
 
 	clk_core_reparent_orphans_nolock();
-- 
2.7.4