2021-11-15 03:49:30

by Li, Meng

Subject: [PATCH] mfd: altera-sysmgr: enable raw spinlock feature for stratix10 platform

When booting up preempt rt kernel on stratix10 platform, there is
below calltrace:
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:969
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 1, name: swapper/0
Preemption disabled at:
[<ffff8000100b25b0>] __setup_irq+0xe0/0x730
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.78-rt54-yocto-preempt-rt #1
Hardware name: SoCFPGA Stratix 10 SoCDK (DT)
Call trace:
......
___might_sleep+0x144/0x180
rt_spin_lock+0x34/0x9c
regmap_lock_spinlock+0x24/0x40
regmap_write+0x48/0x84
a10_eccmgr_irq_unmask+0x34/0x40
......
altr_edac_a10_probe+0x16c/0x2b0
platform_drv_probe+0x60/0xb4
......
ret_from_fork+0x10/0x38

Because regmap_write is invoked under preemption disabled status, and
might trigger sleep. So, enable raw spinlock feature forcibly.

Fixes: f36e789a1f8d ("mfd: altera-sysmgr: Add SOCFPGA System Manager ")
Cc: [email protected]
Signed-off-by: Meng Li <[email protected]>
---
drivers/mfd/altera-sysmgr.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c
index 591b300d9095..8aad5bbb13b3 100644
--- a/drivers/mfd/altera-sysmgr.c
+++ b/drivers/mfd/altera-sysmgr.c
@@ -83,6 +83,9 @@ static struct regmap_config altr_sysmgr_regmap_cfg = {
.fast_io = true,
.use_single_read = true,
.use_single_write = true,
+#ifdef CONFIG_PREEMPT_RT
+ .use_raw_spinlock = true,
+#endif
};

/**
--
2.17.1

2021-11-16 08:26:49

by Li, Meng

Subject: RE: [PATCH] mfd: altera-sysmgr: enable raw spinlock feature for stratix10 platform

I did some improvement for this patch and will send v2 RR.

Thanks,
Limeng

> -----Original Message-----
> From: Li, Meng <[email protected]>
> Sent: Monday, November 15, 2021 11:45 AM
> To: [email protected]; [email protected]; [email protected]
> Cc: [email protected]; Li, Meng <[email protected]>
> Subject: [PATCH] mfd: altera-sysmgr: enable raw spinlock feature for
> stratix10 platform
>
> When booting up preempt rt kernel on stratix10 platform, there is below
> calltrace:
> BUG: sleeping function called from invalid context at
> kernel/locking/rtmutex.c:969
> in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 1, name: swapper/0
> Preemption disabled at:
> [<ffff8000100b25b0>] __setup_irq+0xe0/0x730
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.78-rt54-yocto-preempt-rt
> #1 Hardware name: SoCFPGA Stratix 10 SoCDK (DT) Call trace:
> ......
> ___might_sleep+0x144/0x180
> rt_spin_lock+0x34/0x9c
> regmap_lock_spinlock+0x24/0x40
> regmap_write+0x48/0x84
> a10_eccmgr_irq_unmask+0x34/0x40
> ......
> altr_edac_a10_probe+0x16c/0x2b0
> platform_drv_probe+0x60/0xb4
> ......
> ret_from_fork+0x10/0x38
>
> Because regmap_write is invoked under preemption disabled status, and
> might trigger sleep. So, enable raw spinlock feature forcibly.
>
> Fixes: f36e789a1f8d ("mfd: altera-sysmgr: Add SOCFPGA System Manager ")
> Cc: [email protected]
> Signed-off-by: Meng Li <[email protected]>
> ---
> drivers/mfd/altera-sysmgr.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c index
> 591b300d9095..8aad5bbb13b3 100644
> --- a/drivers/mfd/altera-sysmgr.c
> +++ b/drivers/mfd/altera-sysmgr.c
> @@ -83,6 +83,9 @@ static struct regmap_config altr_sysmgr_regmap_cfg = {
> .fast_io = true,
> .use_single_read = true,
> .use_single_write = true,
> +#ifdef CONFIG_PREEMPT_RT
> + .use_raw_spinlock = true,
> +#endif
> };
>
> /**
> --
> 2.17.1