diff options
| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2011-05-06 11:57:47 +0200 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2011-05-06 18:02:07 -0700 |
| commit | 156229b352b999cafb86a21b50912975e39b7f44 (patch) | |
| tree | dfcbb6c3ede5afd1adfb8fc4efcef37c9f1deb1a /drivers/rtc/rtc-mc13xxx.c | |
| parent | 130107b270f9a8ef1b50e02140a381c44a6abd68 (diff) | |
| download | linux-3.10-156229b352b999cafb86a21b50912975e39b7f44.tar.gz linux-3.10-156229b352b999cafb86a21b50912975e39b7f44.tar.bz2 linux-3.10-156229b352b999cafb86a21b50912975e39b7f44.zip | |
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/rtc-mc13xxx.c')
| -rw-r--r-- | drivers/rtc/rtc-mc13xxx.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c index c5ac03793e7..a1a278bc340 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; } |