diff options
| author | Fabio Estevam <fabio.estevam@freescale.com> | 2015-08-18 15:43:12 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-04 17:51:42 (GMT) |
| commit | 0c727a42043f79db210cdde0366f9137b9c6bf5a (patch) | |
| tree | 532c1a26824d04cb77691d96a6c3c020841a6c99 /drivers/tty/serial | |
| parent | 9ffecb10283508260936b96022d4ee43a7798b4c (diff) | |
| download | linux-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.c | 20 |
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; |