From d3046ba809ce4a3c34d605000cdce48c6ba54b6c Mon Sep 17 00:00:00 2001
From: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Date: Mon, 30 Mar 2015 14:33:45 +0300
Subject: [PATCH] pcmcia: fix a boot time warning in pcmcia cs code
During bootup pcmcia (pccardd) code enforces the following warning
backtrace:
do not call blocking ops when !TASK_RUNNING; state=1 set at [<c0319e74>] pccardd+0xb8/0x3fc
Modules linked in:
CPU: 0 PID: 14 Comm: pccardd Not tainted 4.0.0-rc6+ #11
Hardware name: Sharp-Collie
[<c0105cd8>] (unwind_backtrace) from [<c0103ef8>] (show_stack+0x10/0x14)
[<c0103ef8>] (show_stack) from [<c010e9b8>] (warn_slowpath_common+0x74/0xac)
[<c010e9b8>] (warn_slowpath_common) from [<c010ea20>] (warn_slowpath_fmt+0x30/0x40)
[<c010ea20>] (warn_slowpath_fmt) from [<c012b1b4>] (__might_sleep+0x84/0xa0)
[<c012b1b4>] (__might_sleep) from [<c040fbb0>] (mutex_lock_nested+0x24/0x388)
[<c040fbb0>] (mutex_lock_nested) from [<c0319eb4>] (pccardd+0xf8/0x3fc)
[<c0319eb4>] (pccardd) from [<c0127370>] (kthread+0xdc/0xfc)
[<c0127370>] (kthread) from [<c01013a8>] (ret_from_fork+0x14/0x2c)
---[ end trace fd94911637eed4ba ]---
This happens due to kthread trying to lock mutex in a TASK_INTERRUPTIBLE
state. Limit TASK_INTERRUPTIBLE task state to the schedule() call only,
so that the rest of the code runs in TASK_RUNNING state.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pcmcia/cs.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index 5292db6..367d45e 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -626,8 +626,6 @@ static int pccardd(void *__skt)
unsigned int events;
unsigned int sysfs_events;
- set_current_state(TASK_INTERRUPTIBLE);
-
spin_lock_irqsave(&skt->thread_lock, flags);
events = skt->thread_events;
skt->thread_events = 0;
@@ -675,11 +673,15 @@ static int pccardd(void *__skt)
if (kthread_should_stop())
break;
+ set_current_state(TASK_INTERRUPTIBLE);
+
schedule();
+
+ /* make sure we are running */
+ __set_current_state(TASK_RUNNING);
+
try_to_freeze();
}
- /* make sure we are running before we exit */
- set_current_state(TASK_RUNNING);
/* shut down socket, if a device is still present */
if (skt->state & SOCKET_PRESENT) {
--
2.4.3