* [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
@ 2018-10-21 18:36 Dmitry Osipenko
2018-10-24 10:20 ` Jon Hunter
2018-10-25 14:22 ` Thierry Reding
0 siblings, 2 replies; 5+ messages in thread
From: Dmitry Osipenko @ 2018-10-21 18:36 UTC (permalink / raw)
To: Thierry Reding, Jonathan Hunter; +Cc: linux-tegra, linux-kernel
This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y
and machine (Tegra30) booted with SMP=n or all secondary CPU's are put
offline. Locking isn't needed because it protects atomic operation.
# echo 0 | tee /sys/devices/system/cpu/cpu[1-3]/online
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823
Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
[<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24)
[<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8)
[<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174)
[<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8)
[<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70)
[<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8)
[<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74)
[<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108)
[<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540)
[<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c)
[<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48)
[<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c)
[<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c)
[<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc)
[<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/soc/tegra/pmc.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 1fa840e3d930..1714cd818d69 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -543,9 +543,7 @@ int tegra_powergate_is_powered(unsigned int id)
if (!tegra_powergate_is_valid(id))
return -EINVAL;
- mutex_lock(&pmc->powergates_lock);
status = tegra_powergate_state(id);
- mutex_unlock(&pmc->powergates_lock);
return status;
}
--
2.19.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
2018-10-21 18:36 [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered() Dmitry Osipenko
@ 2018-10-24 10:20 ` Jon Hunter
2018-10-24 10:44 ` Dmitry Osipenko
2018-10-25 14:22 ` Thierry Reding
1 sibling, 1 reply; 5+ messages in thread
From: Jon Hunter @ 2018-10-24 10:20 UTC (permalink / raw)
To: Dmitry Osipenko, Thierry Reding; +Cc: linux-tegra, linux-kernel
On 21/10/2018 19:36, Dmitry Osipenko wrote:
> This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y
> and machine (Tegra30) booted with SMP=n or all secondary CPU's are put
> offline. Locking isn't needed because it protects atomic operation.
>
> # echo 0 | tee /sys/devices/system/cpu/cpu[1-3]/online
>
> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254
> in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> [<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24)
> [<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8)
> [<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174)
> [<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8)
> [<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70)
> [<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8)
> [<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74)
> [<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108)
> [<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540)
> [<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c)
> [<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48)
> [<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c)
> [<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c)
> [<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc)
> [<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/soc/tegra/pmc.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> index 1fa840e3d930..1714cd818d69 100644
> --- a/drivers/soc/tegra/pmc.c
> +++ b/drivers/soc/tegra/pmc.c
> @@ -543,9 +543,7 @@ int tegra_powergate_is_powered(unsigned int id)
> if (!tegra_powergate_is_valid(id))
> return -EINVAL;
>
> - mutex_lock(&pmc->powergates_lock);
> status = tegra_powergate_state(id);
> - mutex_unlock(&pmc->powergates_lock);
>
> return status;
Can we just ...
return tegra_powergate_state(id);
Cheers
Jon
--
nvpublic
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
2018-10-24 10:20 ` Jon Hunter
@ 2018-10-24 10:44 ` Dmitry Osipenko
2018-10-24 10:52 ` Jon Hunter
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Osipenko @ 2018-10-24 10:44 UTC (permalink / raw)
To: Jon Hunter, Thierry Reding; +Cc: linux-tegra, linux-kernel
On 10/24/18 1:20 PM, Jon Hunter wrote:
>
> On 21/10/2018 19:36, Dmitry Osipenko wrote:
>> This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y
>> and machine (Tegra30) booted with SMP=n or all secondary CPU's are put
>> offline. Locking isn't needed because it protects atomic operation.
>>
>> # echo 0 | tee /sys/devices/system/cpu/cpu[1-3]/online
>>
>> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254
>> in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
>> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823
>> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
>> [<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24)
>> [<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8)
>> [<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174)
>> [<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8)
>> [<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70)
>> [<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8)
>> [<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74)
>> [<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108)
>> [<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540)
>> [<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c)
>> [<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48)
>> [<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c)
>> [<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c)
>> [<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc)
>> [<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>> drivers/soc/tegra/pmc.c | 2 --
>> 1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>> index 1fa840e3d930..1714cd818d69 100644
>> --- a/drivers/soc/tegra/pmc.c
>> +++ b/drivers/soc/tegra/pmc.c
>> @@ -543,9 +543,7 @@ int tegra_powergate_is_powered(unsigned int id)
>> if (!tegra_powergate_is_valid(id))
>> return -EINVAL;
>>
>> - mutex_lock(&pmc->powergates_lock);
>> status = tegra_powergate_state(id);
>> - mutex_unlock(&pmc->powergates_lock);
>>
>> return status;
>
> Can we just ...
>
> return tegra_powergate_state(id);
We can, but it is not necessary. Feel free to adjust the code as you wish while applying ;) I deliberately left the 'status' variable because I think that makes code a bit more expressive.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
2018-10-24 10:44 ` Dmitry Osipenko
@ 2018-10-24 10:52 ` Jon Hunter
0 siblings, 0 replies; 5+ messages in thread
From: Jon Hunter @ 2018-10-24 10:52 UTC (permalink / raw)
To: Dmitry Osipenko, Thierry Reding; +Cc: linux-tegra, linux-kernel
On 24/10/2018 11:44, Dmitry Osipenko wrote:
> On 10/24/18 1:20 PM, Jon Hunter wrote:
>>
>> On 21/10/2018 19:36, Dmitry Osipenko wrote:
>>> This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y
>>> and machine (Tegra30) booted with SMP=n or all secondary CPU's are put
>>> offline. Locking isn't needed because it protects atomic operation.
>>>
>>> # echo 0 | tee /sys/devices/system/cpu/cpu[1-3]/online
>>>
>>> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254
>>> in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
>>> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823
>>> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
>>> [<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24)
>>> [<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8)
>>> [<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174)
>>> [<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8)
>>> [<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70)
>>> [<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8)
>>> [<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74)
>>> [<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108)
>>> [<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540)
>>> [<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c)
>>> [<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48)
>>> [<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c)
>>> [<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c)
>>> [<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc)
>>> [<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
>>>
>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>>> ---
>>> drivers/soc/tegra/pmc.c | 2 --
>>> 1 file changed, 2 deletions(-)
>>>
>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>>> index 1fa840e3d930..1714cd818d69 100644
>>> --- a/drivers/soc/tegra/pmc.c
>>> +++ b/drivers/soc/tegra/pmc.c
>>> @@ -543,9 +543,7 @@ int tegra_powergate_is_powered(unsigned int id)
>>> if (!tegra_powergate_is_valid(id))
>>> return -EINVAL;
>>>
>>> - mutex_lock(&pmc->powergates_lock);
>>> status = tegra_powergate_state(id);
>>> - mutex_unlock(&pmc->powergates_lock);
>>>
>>> return status;
>>
>> Can we just ...
>>
>> return tegra_powergate_state(id);
>
> We can, but it is not necessary. Feel free to adjust the code as you wish while applying ;) I deliberately left the 'status' variable because I think that makes code a bit more expressive.
Thierry, please feel free to add my ...
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Personally I would drop the 'status' variable but up to you.
Cheers
Jon
--
nvpublic
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
2018-10-21 18:36 [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered() Dmitry Osipenko
2018-10-24 10:20 ` Jon Hunter
@ 2018-10-25 14:22 ` Thierry Reding
1 sibling, 0 replies; 5+ messages in thread
From: Thierry Reding @ 2018-10-25 14:22 UTC (permalink / raw)
To: Dmitry Osipenko; +Cc: Jonathan Hunter, linux-tegra, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2041 bytes --]
On Sun, Oct 21, 2018 at 09:36:14PM +0300, Dmitry Osipenko wrote:
> This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y
> and machine (Tegra30) booted with SMP=n or all secondary CPU's are put
> offline. Locking isn't needed because it protects atomic operation.
>
> # echo 0 | tee /sys/devices/system/cpu/cpu[1-3]/online
>
> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254
> in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> [<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24)
> [<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8)
> [<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174)
> [<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8)
> [<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70)
> [<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8)
> [<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74)
> [<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108)
> [<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540)
> [<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c)
> [<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48)
> [<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c)
> [<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c)
> [<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc)
> [<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/soc/tegra/pmc.c | 2 --
> 1 file changed, 2 deletions(-)
Applied to for-4.21/soc, thanks.
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-10-25 14:22 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-10-21 18:36 [PATCH v1] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered() Dmitry Osipenko
2018-10-24 10:20 ` Jon Hunter
2018-10-24 10:44 ` Dmitry Osipenko
2018-10-24 10:52 ` Jon Hunter
2018-10-25 14:22 ` Thierry Reding
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox