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authorFabio Estevam <fabio.estevam@freescale.com>2015-08-18 15:43:12 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-04 17:51:42 (GMT)
commit0c727a42043f79db210cdde0366f9137b9c6bf5a (patch)
tree532c1a26824d04cb77691d96a6c3c020841a6c99 /drivers/tty/serial
parent9ffecb10283508260936b96022d4ee43a7798b4c (diff)
downloadlinux-0c727a42043f79db210cdde0366f9137b9c6bf5a.tar.xz
Revert "serial: imx: remove unbalanced clk_prepare"
This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
-rw-r--r--drivers/tty/serial/imx.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index fe3d41c..d0388a0 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1631,12 +1631,12 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
int locked = 1;
int retval;
- retval = clk_prepare_enable(sport->clk_per);
+ retval = clk_enable(sport->clk_per);
if (retval)
return;
- retval = clk_prepare_enable(sport->clk_ipg);
+ retval = clk_enable(sport->clk_ipg);
if (retval) {
- clk_disable_unprepare(sport->clk_per);
+ clk_disable(sport->clk_per);
return;
}
@@ -1675,8 +1675,8 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
- clk_disable_unprepare(sport->clk_ipg);
- clk_disable_unprepare(sport->clk_per);
+ clk_disable(sport->clk_ipg);
+ clk_disable(sport->clk_per);
}
/*
@@ -1777,7 +1777,15 @@ imx_console_setup(struct console *co, char *options)
retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
- clk_disable_unprepare(sport->clk_ipg);
+ clk_disable(sport->clk_ipg);
+ if (retval) {
+ clk_unprepare(sport->clk_ipg);
+ goto error_console;
+ }
+
+ retval = clk_prepare(sport->clk_per);
+ if (retval)
+ clk_disable_unprepare(sport->clk_ipg);
error_console:
return retval;