* BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
@ 2016-04-30 17:24 ` H. Nikolaus Schaller
0 siblings, 0 replies; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-04-30 17:24 UTC (permalink / raw)
To: linux-omap, Roger Quadros, Mike Turquette, LKML
Cc: kernel, Discussions about the Letux Kernel
Hi,
I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
[ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
[ 5.830974] driver_register 'ehci-omap'
[ 5.895849] driver_register 'wl1271_sdio'
[ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
[ 5.896876] 4 locks held by udevd/994:
[ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
[ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
[ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
[ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
[ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
[ 5.897048] Preemption disabled at:[< (null)>] (null)
[ 5.897051]
[ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
[ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
[ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
[ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
[ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
[ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
[ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
[ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
[ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
[ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
[ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
[ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
[ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
[ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
[ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
[ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
[ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
[ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
[ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
[ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
[ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
[ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
[ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
[ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
[ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
[ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
[ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
[ 5.912697] ------------[ cut here ]------------
[ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
[ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
A liitle analysis of the code shows me:
* udevd tries to initialize some (usb driver?) module
* this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
* which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
* this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
* but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
* which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
* and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
* and that is a mutex_try_lock
So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
Please fix.
Thank you,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
* BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
@ 2016-04-30 17:24 ` H. Nikolaus Schaller
0 siblings, 0 replies; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-04-30 17:24 UTC (permalink / raw)
To: linux-omap, Roger Quadros, Mike Turquette, LKML
Cc: kernel, Discussions about the Letux Kernel
Hi,
I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
[ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
[ 5.830974] driver_register 'ehci-omap'
[ 5.895849] driver_register 'wl1271_sdio'
[ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
[ 5.896876] 4 locks held by udevd/994:
[ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
[ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
[ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
[ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
[ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
[ 5.897048] Preemption disabled at:[< (null)>] (null)
[ 5.897051]
[ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
[ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
[ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
[ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
[ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
[ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
[ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
[ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
[ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
[ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
[ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
[ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
[ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
[ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
[ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
[ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
[ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
[ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
[ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
[ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
[ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
[ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
[ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
[ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
[ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
[ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
[ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
[ 5.912697] ------------[ cut here ]------------
[ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
[ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
A liitle analysis of the code shows me:
* udevd tries to initialize some (usb driver?) module
* this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
* which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
* this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
* but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
* which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
* and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
* and that is a mutex_try_lock
So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
Please fix.
Thank you,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
2016-04-30 17:24 ` H. Nikolaus Schaller
@ 2016-05-02 12:41 ` Roger Quadros
-1 siblings, 0 replies; 10+ messages in thread
From: Roger Quadros @ 2016-05-02 12:41 UTC (permalink / raw)
To: H. Nikolaus Schaller, linux-omap, Mike Turquette, LKML
Cc: kernel, Discussions about the Letux Kernel
Hi Nikolaus,
On 30/04/16 20:24, H. Nikolaus Schaller wrote:
> Hi,
> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>
> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
> [ 5.830974] driver_register 'ehci-omap'
> [ 5.895849] driver_register 'wl1271_sdio'
> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
> [ 5.896876] 4 locks held by udevd/994:
> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
> [ 5.897048] Preemption disabled at:[< (null)>] (null)
> [ 5.897051]
> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
> [ 5.912697] ------------[ cut here ]------------
> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>
> A liitle analysis of the code shows me:
>
> * udevd tries to initialize some (usb driver?) module
> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
> * and that is a mutex_try_lock
>
> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>
> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>
> Please fix.
>
> Thank you,
> Nikolaus
Does this patch fix it for you?
--
cheers,
-roger
diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
index b7b3e8e..c30290f 100644
--- a/drivers/mfd/omap-usb-tll.c
+++ b/drivers/mfd/omap-usb-tll.c
@@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
if (IS_ERR(tll->ch_clk[i]))
dev_dbg(dev, "can't get clock : %s\n", clkname);
+ else
+ clk_prepare(tll->ch_clk[i]);
}
pm_runtime_put_sync(dev);
@@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
tll_dev = NULL;
spin_unlock(&tll_lock);
- for (i = 0; i < tll->nch; i++)
- if (!IS_ERR(tll->ch_clk[i]))
+ for (i = 0; i < tll->nch; i++) {
+ if (!IS_ERR(tll->ch_clk[i])) {
+ clk_unprepare(tll->ch_clk[i]);
clk_put(tll->ch_clk[i]);
+ }
+ }
pm_runtime_disable(&pdev->dev);
return 0;
@@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
if (IS_ERR(tll->ch_clk[i]))
continue;
- r = clk_prepare_enable(tll->ch_clk[i]);
+ r = clk_enable(tll->ch_clk[i]);
if (r) {
dev_err(tll_dev,
"Error enabling ch %d clock: %d\n", i, r);
@@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
for (i = 0; i < tll->nch; i++) {
if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
if (!IS_ERR(tll->ch_clk[i]))
- clk_disable_unprepare(tll->ch_clk[i]);
+ clk_disable(tll->ch_clk[i]);
}
}
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
@ 2016-05-02 12:41 ` Roger Quadros
0 siblings, 0 replies; 10+ messages in thread
From: Roger Quadros @ 2016-05-02 12:41 UTC (permalink / raw)
To: H. Nikolaus Schaller, linux-omap, Mike Turquette, LKML
Cc: kernel, Discussions about the Letux Kernel
Hi Nikolaus,
On 30/04/16 20:24, H. Nikolaus Schaller wrote:
> Hi,
> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>
> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
> [ 5.830974] driver_register 'ehci-omap'
> [ 5.895849] driver_register 'wl1271_sdio'
> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
> [ 5.896876] 4 locks held by udevd/994:
> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
> [ 5.897048] Preemption disabled at:[< (null)>] (null)
> [ 5.897051]
> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
> [ 5.912697] ------------[ cut here ]------------
> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>
> A liitle analysis of the code shows me:
>
> * udevd tries to initialize some (usb driver?) module
> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
> * and that is a mutex_try_lock
>
> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>
> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>
> Please fix.
>
> Thank you,
> Nikolaus
Does this patch fix it for you?
--
cheers,
-roger
diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
index b7b3e8e..c30290f 100644
--- a/drivers/mfd/omap-usb-tll.c
+++ b/drivers/mfd/omap-usb-tll.c
@@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
if (IS_ERR(tll->ch_clk[i]))
dev_dbg(dev, "can't get clock : %s\n", clkname);
+ else
+ clk_prepare(tll->ch_clk[i]);
}
pm_runtime_put_sync(dev);
@@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
tll_dev = NULL;
spin_unlock(&tll_lock);
- for (i = 0; i < tll->nch; i++)
- if (!IS_ERR(tll->ch_clk[i]))
+ for (i = 0; i < tll->nch; i++) {
+ if (!IS_ERR(tll->ch_clk[i])) {
+ clk_unprepare(tll->ch_clk[i]);
clk_put(tll->ch_clk[i]);
+ }
+ }
pm_runtime_disable(&pdev->dev);
return 0;
@@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
if (IS_ERR(tll->ch_clk[i]))
continue;
- r = clk_prepare_enable(tll->ch_clk[i]);
+ r = clk_enable(tll->ch_clk[i]);
if (r) {
dev_err(tll_dev,
"Error enabling ch %d clock: %d\n", i, r);
@@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
for (i = 0; i < tll->nch; i++) {
if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
if (!IS_ERR(tll->ch_clk[i]))
- clk_disable_unprepare(tll->ch_clk[i]);
+ clk_disable(tll->ch_clk[i]);
}
}
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
2016-05-02 12:41 ` Roger Quadros
@ 2016-05-02 13:03 ` H. Nikolaus Schaller
-1 siblings, 0 replies; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-05-02 13:03 UTC (permalink / raw)
To: Roger Quadros
Cc: linux-omap, Mike Turquette, LKML, kernel,
Discussions about the Letux Kernel
Hi Roger,
> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>
> Hi Nikolaus,
>
> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>> Hi,
>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>
>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>> [ 5.830974] driver_register 'ehci-omap'
>> [ 5.895849] driver_register 'wl1271_sdio'
>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>> [ 5.896876] 4 locks held by udevd/994:
>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>> [ 5.897051]
>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>> [ 5.912697] ------------[ cut here ]------------
>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>
>> A liitle analysis of the code shows me:
>>
>> * udevd tries to initialize some (usb driver?) module
>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>> * and that is a mutex_try_lock
>>
>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>
>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>
>> Please fix.
>>
>> Thank you,
>> Nikolaus
>
> Does this patch fix it for you?
>
> --
> cheers,
> -roger
>
> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
> index b7b3e8e..c30290f 100644
> --- a/drivers/mfd/omap-usb-tll.c
> +++ b/drivers/mfd/omap-usb-tll.c
> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>
> if (IS_ERR(tll->ch_clk[i]))
> dev_dbg(dev, "can't get clock : %s\n", clkname);
> + else
> + clk_prepare(tll->ch_clk[i]);
> }
>
> pm_runtime_put_sync(dev);
> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
> tll_dev = NULL;
> spin_unlock(&tll_lock);
>
> - for (i = 0; i < tll->nch; i++)
> - if (!IS_ERR(tll->ch_clk[i]))
> + for (i = 0; i < tll->nch; i++) {
> + if (!IS_ERR(tll->ch_clk[i])) {
> + clk_unprepare(tll->ch_clk[i]);
> clk_put(tll->ch_clk[i]);
> + }
> + }
>
> pm_runtime_disable(&pdev->dev);
> return 0;
> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
> if (IS_ERR(tll->ch_clk[i]))
> continue;
>
> - r = clk_prepare_enable(tll->ch_clk[i]);
> + r = clk_enable(tll->ch_clk[i]);
> if (r) {
> dev_err(tll_dev,
> "Error enabling ch %d clock: %d\n", i, r);
> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
> for (i = 0; i < tll->nch; i++) {
> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
> if (!IS_ERR(tll->ch_clk[i]))
> - clk_disable_unprepare(tll->ch_clk[i]);
> + clk_disable(tll->ch_clk[i]);
> }
> }
I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
BR and thanks,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
@ 2016-05-02 13:03 ` H. Nikolaus Schaller
0 siblings, 0 replies; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-05-02 13:03 UTC (permalink / raw)
To: Roger Quadros
Cc: linux-omap, Mike Turquette, LKML, kernel,
Discussions about the Letux Kernel
Hi Roger,
> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>
> Hi Nikolaus,
>
> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>> Hi,
>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>
>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>> [ 5.830974] driver_register 'ehci-omap'
>> [ 5.895849] driver_register 'wl1271_sdio'
>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>> [ 5.896876] 4 locks held by udevd/994:
>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>> [ 5.897051]
>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>> [ 5.912697] ------------[ cut here ]------------
>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>
>> A liitle analysis of the code shows me:
>>
>> * udevd tries to initialize some (usb driver?) module
>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>> * and that is a mutex_try_lock
>>
>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>
>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>
>> Please fix.
>>
>> Thank you,
>> Nikolaus
>
> Does this patch fix it for you?
>
> --
> cheers,
> -roger
>
> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
> index b7b3e8e..c30290f 100644
> --- a/drivers/mfd/omap-usb-tll.c
> +++ b/drivers/mfd/omap-usb-tll.c
> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>
> if (IS_ERR(tll->ch_clk[i]))
> dev_dbg(dev, "can't get clock : %s\n", clkname);
> + else
> + clk_prepare(tll->ch_clk[i]);
> }
>
> pm_runtime_put_sync(dev);
> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
> tll_dev = NULL;
> spin_unlock(&tll_lock);
>
> - for (i = 0; i < tll->nch; i++)
> - if (!IS_ERR(tll->ch_clk[i]))
> + for (i = 0; i < tll->nch; i++) {
> + if (!IS_ERR(tll->ch_clk[i])) {
> + clk_unprepare(tll->ch_clk[i]);
> clk_put(tll->ch_clk[i]);
> + }
> + }
>
> pm_runtime_disable(&pdev->dev);
> return 0;
> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
> if (IS_ERR(tll->ch_clk[i]))
> continue;
>
> - r = clk_prepare_enable(tll->ch_clk[i]);
> + r = clk_enable(tll->ch_clk[i]);
> if (r) {
> dev_err(tll_dev,
> "Error enabling ch %d clock: %d\n", i, r);
> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
> for (i = 0; i < tll->nch; i++) {
> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
> if (!IS_ERR(tll->ch_clk[i]))
> - clk_disable_unprepare(tll->ch_clk[i]);
> + clk_disable(tll->ch_clk[i]);
> }
> }
I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
BR and thanks,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Kernel] BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
2016-05-02 13:03 ` H. Nikolaus Schaller
(?)
@ 2016-05-08 6:46 ` H. Nikolaus Schaller
2016-05-09 8:31 ` Roger Quadros
-1 siblings, 1 reply; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-05-08 6:46 UTC (permalink / raw)
To: Roger Quadros
Cc: Discussions about the Letux Kernel, linux-omap, Mike Turquette,
LKML, kernel
Hi Roger,
> Am 02.05.2016 um 15:03 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>
> Hi Roger,
>
>> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>>
>> Hi Nikolaus,
>>
>> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>>> Hi,
>>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>>
>>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>>> [ 5.830974] driver_register 'ehci-omap'
>>> [ 5.895849] driver_register 'wl1271_sdio'
>>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>>> [ 5.896876] 4 locks held by udevd/994:
>>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>>> [ 5.897051]
>>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>>> [ 5.912697] ------------[ cut here ]------------
>>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>>
>>> A liitle analysis of the code shows me:
>>>
>>> * udevd tries to initialize some (usb driver?) module
>>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>>> * and that is a mutex_try_lock
>>>
>>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>>
>>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>>
>>> Please fix.
>>>
>>> Thank you,
>>> Nikolaus
>>
>> Does this patch fix it for you?
>>
>> --
>> cheers,
>> -roger
>>
>> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
>> index b7b3e8e..c30290f 100644
>> --- a/drivers/mfd/omap-usb-tll.c
>> +++ b/drivers/mfd/omap-usb-tll.c
>> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>
>> if (IS_ERR(tll->ch_clk[i]))
>> dev_dbg(dev, "can't get clock : %s\n", clkname);
>> + else
>> + clk_prepare(tll->ch_clk[i]);
>> }
>>
>> pm_runtime_put_sync(dev);
>> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
>> tll_dev = NULL;
>> spin_unlock(&tll_lock);
>>
>> - for (i = 0; i < tll->nch; i++)
>> - if (!IS_ERR(tll->ch_clk[i]))
>> + for (i = 0; i < tll->nch; i++) {
>> + if (!IS_ERR(tll->ch_clk[i])) {
>> + clk_unprepare(tll->ch_clk[i]);
>> clk_put(tll->ch_clk[i]);
>> + }
>> + }
>>
>> pm_runtime_disable(&pdev->dev);
>> return 0;
>> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
>> if (IS_ERR(tll->ch_clk[i]))
>> continue;
>>
>> - r = clk_prepare_enable(tll->ch_clk[i]);
>> + r = clk_enable(tll->ch_clk[i]);
>> if (r) {
>> dev_err(tll_dev,
>> "Error enabling ch %d clock: %d\n", i, r);
>> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
>> for (i = 0; i < tll->nch; i++) {
>> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
>> if (!IS_ERR(tll->ch_clk[i]))
>> - clk_disable_unprepare(tll->ch_clk[i]);
>> + clk_disable(tll->ch_clk[i]);
>> }
>> }
>
> I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
I have it in my tree for a while and did no longer observe the BUG.
And I did not experience side effects (e.g. usb not working...).
So I think it works and solves the issue.
BR and thanks,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Kernel] BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
2016-05-08 6:46 ` [Kernel] " H. Nikolaus Schaller
@ 2016-05-09 8:31 ` Roger Quadros
0 siblings, 0 replies; 10+ messages in thread
From: Roger Quadros @ 2016-05-09 8:31 UTC (permalink / raw)
To: H. Nikolaus Schaller
Cc: Discussions about the Letux Kernel, linux-omap, LKML, kernel, mturquette
Hi Nikolaus,
On 08/05/16 09:46, H. Nikolaus Schaller wrote:
> Hi Roger,
>
>> Am 02.05.2016 um 15:03 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>
>> Hi Roger,
>>
>>> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>>>
>>> Hi Nikolaus,
>>>
>>> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>>>> Hi,
>>>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>>>
>>>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>>>> [ 5.830974] driver_register 'ehci-omap'
>>>> [ 5.895849] driver_register 'wl1271_sdio'
>>>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>>>> [ 5.896876] 4 locks held by udevd/994:
>>>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>>>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>>>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>>>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>>>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>>>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>>>> [ 5.897051]
>>>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>>>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>>>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>>>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>>>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>>>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>>>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>>>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>>>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>>>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>>>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>>>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>>>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>>>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>>>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>>>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>>>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>>>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>>>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>>>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>>>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>>>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>>>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>>>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>>>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>>>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>>>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>>>> [ 5.912697] ------------[ cut here ]------------
>>>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>>>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>>>
>>>> A liitle analysis of the code shows me:
>>>>
>>>> * udevd tries to initialize some (usb driver?) module
>>>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>>>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>>>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>>>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>>>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>>>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>>>> * and that is a mutex_try_lock
>>>>
>>>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>>>
>>>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>>>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>>>
>>>> Please fix.
>>>>
>>>> Thank you,
>>>> Nikolaus
>>>
>>> Does this patch fix it for you?
>>>
>>> --
>>> cheers,
>>> -roger
>>>
>>> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
>>> index b7b3e8e..c30290f 100644
>>> --- a/drivers/mfd/omap-usb-tll.c
>>> +++ b/drivers/mfd/omap-usb-tll.c
>>> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>>
>>> if (IS_ERR(tll->ch_clk[i]))
>>> dev_dbg(dev, "can't get clock : %s\n", clkname);
>>> + else
>>> + clk_prepare(tll->ch_clk[i]);
>>> }
>>>
>>> pm_runtime_put_sync(dev);
>>> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
>>> tll_dev = NULL;
>>> spin_unlock(&tll_lock);
>>>
>>> - for (i = 0; i < tll->nch; i++)
>>> - if (!IS_ERR(tll->ch_clk[i]))
>>> + for (i = 0; i < tll->nch; i++) {
>>> + if (!IS_ERR(tll->ch_clk[i])) {
>>> + clk_unprepare(tll->ch_clk[i]);
>>> clk_put(tll->ch_clk[i]);
>>> + }
>>> + }
>>>
>>> pm_runtime_disable(&pdev->dev);
>>> return 0;
>>> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
>>> if (IS_ERR(tll->ch_clk[i]))
>>> continue;
>>>
>>> - r = clk_prepare_enable(tll->ch_clk[i]);
>>> + r = clk_enable(tll->ch_clk[i]);
>>> if (r) {
>>> dev_err(tll_dev,
>>> "Error enabling ch %d clock: %d\n", i, r);
>>> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
>>> for (i = 0; i < tll->nch; i++) {
>>> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
>>> if (!IS_ERR(tll->ch_clk[i]))
>>> - clk_disable_unprepare(tll->ch_clk[i]);
>>> + clk_disable(tll->ch_clk[i]);
>>> }
>>> }
>>
>> I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
>
> I have it in my tree for a while and did no longer observe the BUG.
> And I did not experience side effects (e.g. usb not working...).
>
> So I think it works and solves the issue.
>
Thanks for the bug report and the test.
Official patch is on its way.
cheers,
-roger
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Kernel] BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
@ 2016-05-09 8:31 ` Roger Quadros
0 siblings, 0 replies; 10+ messages in thread
From: Roger Quadros @ 2016-05-09 8:31 UTC (permalink / raw)
To: H. Nikolaus Schaller
Cc: Discussions about the Letux Kernel, linux-omap, LKML, kernel, mturquette
Hi Nikolaus,
On 08/05/16 09:46, H. Nikolaus Schaller wrote:
> Hi Roger,
>
>> Am 02.05.2016 um 15:03 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>
>> Hi Roger,
>>
>>> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>>>
>>> Hi Nikolaus,
>>>
>>> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>>>> Hi,
>>>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>>>
>>>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>>>> [ 5.830974] driver_register 'ehci-omap'
>>>> [ 5.895849] driver_register 'wl1271_sdio'
>>>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>>>> [ 5.896876] 4 locks held by udevd/994:
>>>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>>>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>>>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>>>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>>>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>>>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>>>> [ 5.897051]
>>>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>>>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>>>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>>>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>>>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>>>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>>>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>>>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>>>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>>>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>>>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>>>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>>>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>>>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>>>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>>>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>>>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>>>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>>>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>>>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>>>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>>>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>>>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>>>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>>>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>>>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>>>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>>>> [ 5.912697] ------------[ cut here ]------------
>>>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>>>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>>>
>>>> A liitle analysis of the code shows me:
>>>>
>>>> * udevd tries to initialize some (usb driver?) module
>>>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>>>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>>>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>>>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>>>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>>>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>>>> * and that is a mutex_try_lock
>>>>
>>>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>>>
>>>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>>>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>>>
>>>> Please fix.
>>>>
>>>> Thank you,
>>>> Nikolaus
>>>
>>> Does this patch fix it for you?
>>>
>>> --
>>> cheers,
>>> -roger
>>>
>>> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
>>> index b7b3e8e..c30290f 100644
>>> --- a/drivers/mfd/omap-usb-tll.c
>>> +++ b/drivers/mfd/omap-usb-tll.c
>>> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>>
>>> if (IS_ERR(tll->ch_clk[i]))
>>> dev_dbg(dev, "can't get clock : %s\n", clkname);
>>> + else
>>> + clk_prepare(tll->ch_clk[i]);
>>> }
>>>
>>> pm_runtime_put_sync(dev);
>>> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
>>> tll_dev = NULL;
>>> spin_unlock(&tll_lock);
>>>
>>> - for (i = 0; i < tll->nch; i++)
>>> - if (!IS_ERR(tll->ch_clk[i]))
>>> + for (i = 0; i < tll->nch; i++) {
>>> + if (!IS_ERR(tll->ch_clk[i])) {
>>> + clk_unprepare(tll->ch_clk[i]);
>>> clk_put(tll->ch_clk[i]);
>>> + }
>>> + }
>>>
>>> pm_runtime_disable(&pdev->dev);
>>> return 0;
>>> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
>>> if (IS_ERR(tll->ch_clk[i]))
>>> continue;
>>>
>>> - r = clk_prepare_enable(tll->ch_clk[i]);
>>> + r = clk_enable(tll->ch_clk[i]);
>>> if (r) {
>>> dev_err(tll_dev,
>>> "Error enabling ch %d clock: %d\n", i, r);
>>> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
>>> for (i = 0; i < tll->nch; i++) {
>>> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
>>> if (!IS_ERR(tll->ch_clk[i]))
>>> - clk_disable_unprepare(tll->ch_clk[i]);
>>> + clk_disable(tll->ch_clk[i]);
>>> }
>>> }
>>
>> I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
>
> I have it in my tree for a while and did no longer observe the BUG.
> And I did not experience side effects (e.g. usb not working...).
>
> So I think it works and solves the issue.
>
Thanks for the bug report and the test.
Official patch is on its way.
cheers,
-roger
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Kernel] BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock
2016-05-09 8:31 ` Roger Quadros
(?)
@ 2016-05-09 8:46 ` H. Nikolaus Schaller
-1 siblings, 0 replies; 10+ messages in thread
From: H. Nikolaus Schaller @ 2016-05-09 8:46 UTC (permalink / raw)
To: Roger Quadros
Cc: Discussions about the Letux Kernel, linux-omap, LKML, kernel, mturquette
Hi Roger,
> Am 09.05.2016 um 10:31 schrieb Roger Quadros <rogerq@ti.com>:
>
> Hi Nikolaus,
>
> On 08/05/16 09:46, H. Nikolaus Schaller wrote:
>> Hi Roger,
>>
>>> Am 02.05.2016 um 15:03 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>>
>>> Hi Roger,
>>>
>>>> Am 02.05.2016 um 14:41 schrieb Roger Quadros <rogerq@ti.com>:
>>>>
>>>> Hi Nikolaus,
>>>>
>>>> On 30/04/16 20:24, H. Nikolaus Schaller wrote:
>>>>> Hi,
>>>>> I have observed this kernel oops on an omap5 board from time to time (approx. 1% of boot processes):
>>>>>
>>>>> [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver
>>>>> [ 5.830974] driver_register 'ehci-omap'
>>>>> [ 5.895849] driver_register 'wl1271_sdio'
>>>>> [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002
>>>>> [ 5.896876] 4 locks held by udevd/994:
>>>>> [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac
>>>>> [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac
>>>>> [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0
>>>>> [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0
>>>>> [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine
>>>>> [ 5.897048] Preemption disabled at:[< (null)>] (null)
>>>>> [ 5.897051]
>>>>> [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233
>>>>> [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree)
>>>>> [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14)
>>>>> [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0)
>>>>> [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0)
>>>>> [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4)
>>>>> [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0)
>>>>> [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20)
>>>>> [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c)
>>>>> [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0)
>>>>> [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28)
>>>>> [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0)
>>>>> [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c)
>>>>> [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40)
>>>>> [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68)
>>>>> [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88)
>>>>> [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec)
>>>>> [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64)
>>>>> [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70)
>>>>> [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac)
>>>>> [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84)
>>>>> [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4)
>>>>> [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4)
>>>>> [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8)
>>>>> [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0)
>>>>> [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90)
>>>>> [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c)
>>>>> [ 5.912697] ------------[ cut here ]------------
>>>>> [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58
>>>>> [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count())
>>>>>
>>>>> A liitle analysis of the code shows me:
>>>>>
>>>>> * udevd tries to initialize some (usb driver?) module
>>>>> * this calls usbhs_runtime_resume: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-host.c#L310
>>>>> * which calls omap_tll_enable: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L403
>>>>> * this does a spinlock: http://lxr.free-electrons.com/source/drivers/mfd/omap-usb-tll.c#L413
>>>>> * but calls clk_prepare_enable: http://lxr.free-electrons.com/source/include/linux/clk.h#L467
>>>>> * which calls: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L658
>>>>> * and there is a another lock being tried in clk_prepare_lock: http://lxr.free-electrons.com/source/drivers/clk/clk.c#L91
>>>>> * and that is a mutex_try_lock
>>>>>
>>>>> So the lock dependency report is very valid. Inside a spinlock, there is a mutex_try_lock.
>>>>>
>>>>> It appears as if the spinlock was introduced in 2008 by 76a0775d46da052f123b8598a3dfc3b330b8de4f
>>>>> And the mutex in 2013 by 533ddeb1e86f506129ee388a6cc13796dcf31311
>>>>>
>>>>> Please fix.
>>>>>
>>>>> Thank you,
>>>>> Nikolaus
>>>>
>>>> Does this patch fix it for you?
>>>>
>>>> --
>>>> cheers,
>>>> -roger
>>>>
>>>> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
>>>> index b7b3e8e..c30290f 100644
>>>> --- a/drivers/mfd/omap-usb-tll.c
>>>> +++ b/drivers/mfd/omap-usb-tll.c
>>>> @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>>>
>>>> if (IS_ERR(tll->ch_clk[i]))
>>>> dev_dbg(dev, "can't get clock : %s\n", clkname);
>>>> + else
>>>> + clk_prepare(tll->ch_clk[i]);
>>>> }
>>>>
>>>> pm_runtime_put_sync(dev);
>>>> @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev)
>>>> tll_dev = NULL;
>>>> spin_unlock(&tll_lock);
>>>>
>>>> - for (i = 0; i < tll->nch; i++)
>>>> - if (!IS_ERR(tll->ch_clk[i]))
>>>> + for (i = 0; i < tll->nch; i++) {
>>>> + if (!IS_ERR(tll->ch_clk[i])) {
>>>> + clk_unprepare(tll->ch_clk[i]);
>>>> clk_put(tll->ch_clk[i]);
>>>> + }
>>>> + }
>>>>
>>>> pm_runtime_disable(&pdev->dev);
>>>> return 0;
>>>> @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
>>>> if (IS_ERR(tll->ch_clk[i]))
>>>> continue;
>>>>
>>>> - r = clk_prepare_enable(tll->ch_clk[i]);
>>>> + r = clk_enable(tll->ch_clk[i]);
>>>> if (r) {
>>>> dev_err(tll_dev,
>>>> "Error enabling ch %d clock: %d\n", i, r);
>>>> @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
>>>> for (i = 0; i < tll->nch; i++) {
>>>> if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
>>>> if (!IS_ERR(tll->ch_clk[i]))
>>>> - clk_disable_unprepare(tll->ch_clk[i]);
>>>> + clk_disable(tll->ch_clk[i]);
>>>> }
>>>> }
>>>
>>> I will give it a try. Since it is sporadic I can tell only after some days of use if it did not happen any more.
>>
>> I have it in my tree for a while and did no longer observe the BUG.
>> And I did not experience side effects (e.g. usb not working...).
>>
>> So I think it works and solves the issue.
>>
>
> Thanks for the bug report and the test.
> Official patch is on its way.
>
Great! Thanks,
Nikolaus
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2016-05-09 8:46 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-30 17:24 BUG: spinlock vs. mutex in SyS_finit_module / usbhs_runtime_resume / omap_tll_enable / clk_prepare_lock H. Nikolaus Schaller
2016-04-30 17:24 ` H. Nikolaus Schaller
2016-05-02 12:41 ` Roger Quadros
2016-05-02 12:41 ` Roger Quadros
2016-05-02 13:03 ` H. Nikolaus Schaller
2016-05-02 13:03 ` H. Nikolaus Schaller
2016-05-08 6:46 ` [Kernel] " H. Nikolaus Schaller
2016-05-09 8:31 ` Roger Quadros
2016-05-09 8:31 ` Roger Quadros
2016-05-09 8:46 ` H. Nikolaus Schaller
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