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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2011-05-06 11:57:47 +0200
committerJohn Stultz <john.stultz@linaro.org>2011-05-06 18:02:07 -0700
commit156229b352b999cafb86a21b50912975e39b7f44 (patch)
treedfcbb6c3ede5afd1adfb8fc4efcef37c9f1deb1a /drivers/rtc
parent130107b270f9a8ef1b50e02140a381c44a6abd68 (diff)
rtc: mc13xxx: Don't call rtc_device_register while holding lock
Since commit f44f7f9 (RTC: Initialize kernel state from RTC) rtc_device_register reads the programmed alarm. As reading the alarm needs to take the mc13xxx lock, release it before calling rtc_device_register. This fixes a deadlock during boot: INFO: task swapper:1 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. swapper D c02b175c 0 1 0 0x00000000 [<c02b175c>] (schedule+0x304/0x4f4) from [<c02b25a8>] (__mutex_lock_slowpath+0x7c/0x110) [<c02b25a8>] (__mutex_lock_slowpath+0x7c/0x110) from [<c020b4cc>] (mc13xxx_rtc_read_time+0x1c/0x118) [<c020b4cc>] (mc13xxx_rtc_read_time+0x1c/0x118) from [<c0208f04>] (__rtc_read_time+0x58/0x5c) [<c0208f04>] (__rtc_read_time+0x58/0x5c) from [<c0209508>] (rtc_read_time+0x30/0x48) [<c0209508>] (rtc_read_time+0x30/0x48) from [<c0209dd4>] (__rtc_read_alarm+0x1c/0x290) [<c0209dd4>] (__rtc_read_alarm+0x1c/0x290) from [<c0208d58>] (rtc_device_register+0x150/0x27c) [<c0208d58>] (rtc_device_register+0x150/0x27c) from [<c02b0b74>] (mc13xxx_rtc_probe+0x128/0x17c) [<c02b0b74>] (mc13xxx_rtc_probe+0x128/0x17c) from [<c01d5280>] (platform_drv_probe+0x1c/0x24) [<c01d5280>] (platform_drv_probe+0x1c/0x24) from [<c01d3e58>] (driver_probe_device+0x80/0x1a8) [<c01d3e58>] (driver_probe_device+0x80/0x1a8) from [<c01d400c>] (__driver_attach+0x8c/0x90) [<c01d400c>] (__driver_attach+0x8c/0x90) from [<c01d3654>] (bus_for_each_dev+0x60/0x8c) [<c01d3654>] (bus_for_each_dev+0x60/0x8c) from [<c01d2f6c>] (bus_add_driver+0x180/0x248) [<c01d2f6c>] (bus_add_driver+0x180/0x248) from [<c01d4664>] (driver_register+0x70/0x15c) [<c01d4664>] (driver_register+0x70/0x15c) from [<c01d5700>] (platform_driver_probe+0x18/0x98) [<c01d5700>] (platform_driver_probe+0x18/0x98) from [<c00273a8>] (do_one_initcall+0x2c/0x168) [<c00273a8>] (do_one_initcall+0x2c/0x168) from [<c00083ac>] (kernel_init+0xa0/0x150) [<c00083ac>] (kernel_init+0xa0/0x150) from [<c0033ff8>] (kernel_thread_exit+0x0/0x8) Reported-by: Vagrant Cascadian <vagrant@debian.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Closes: http://bugs.debian.org/625804 [Tweaked commit log -jstultz] Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-mc13xxx.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index c5ac03793e79..a1a278bc340d 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -349,11 +349,15 @@ static int __devinit mc13xxx_rtc_probe(struct platform_device *pdev)
if (ret)
goto err_alarm_irq_request;
+ mc13xxx_unlock(mc13xxx);
+
priv->rtc = rtc_device_register(pdev->name,
&pdev->dev, &mc13xxx_rtc_ops, THIS_MODULE);
if (IS_ERR(priv->rtc)) {
ret = PTR_ERR(priv->rtc);
+ mc13xxx_lock(mc13xxx);
+
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
err_alarm_irq_request:
@@ -365,12 +369,12 @@ err_reset_irq_status:
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
err_reset_irq_request:
+ mc13xxx_unlock(mc13xxx);
+
platform_set_drvdata(pdev, NULL);
kfree(priv);
}
- mc13xxx_unlock(mc13xxx);
-
return ret;
}