2020-10-20 21:21:08

by Greentime Hu

[permalink] [raw]
Subject: [PATCH] irqchip/sifive-plic: Fix broken irq_set_affinity() callback

It will always enable the interrupt after calling plic_set_affinity()
however it should set to it previous setting. Staying disabled or enabled.

This patch can also fix this pwm hang issue in Unleashed board.

[ 919.015783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 919.020922] rcu: 0-...0: (0 ticks this GP)
idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=105807
[ 919.030295] (detected by 1, t=225825 jiffies, g=1561, q=3496)
[ 919.036109] Task dump for CPU 0:
[ 919.039321] kworker/0:1 R running task 0 30 2 0x00000008
[ 919.046359] Workqueue: events set_brightness_delayed
[ 919.051302] Call Trace:
[ 919.053738] [<ffffffe000930d92>] __schedule+0x194/0x4de
[ 982.035783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 982.040923] rcu: 0-...0: (0 ticks this GP)
idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=113325
[ 982.050294] (detected by 1, t=241580 jiffies, g=1561, q=3509)
[ 982.056108] Task dump for CPU 0:
[ 982.059321] kworker/0:1 R running task 0 30 2 0x00000008
[ 982.066359] Workqueue: events set_brightness_delayed
[ 982.071302] Call Trace:
[ 982.073739] [<ffffffe000930d92>] __schedule+0x194/0x4de
[..]

Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow")
Signed-off-by: Greentime Hu <[email protected]>
---
drivers/irqchip/irq-sifive-plic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index eaa3e9fe54e9..4048657ece0a 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -151,7 +151,7 @@ static int plic_set_affinity(struct irq_data *d,
return -EINVAL;

plic_irq_toggle(&priv->lmask, d, 0);
- plic_irq_toggle(cpumask_of(cpu), d, 1);
+ plic_irq_toggle(cpumask_of(cpu), d, !irqd_irq_masked(d));

irq_data_update_effective_affinity(d, cpumask_of(cpu));

--
2.28.0


2020-10-20 21:42:10

by Anup Patel

[permalink] [raw]
Subject: Re: [PATCH] irqchip/sifive-plic: Fix broken irq_set_affinity() callback

On Tue, Oct 20, 2020 at 1:45 PM Greentime Hu <[email protected]> wrote:
>
> It will always enable the interrupt after calling plic_set_affinity()
> however it should set to it previous setting. Staying disabled or enabled.
>
> This patch can also fix this pwm hang issue in Unleashed board.
>
> [ 919.015783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 919.020922] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=105807
> [ 919.030295] (detected by 1, t=225825 jiffies, g=1561, q=3496)
> [ 919.036109] Task dump for CPU 0:
> [ 919.039321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 919.046359] Workqueue: events set_brightness_delayed
> [ 919.051302] Call Trace:
> [ 919.053738] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [ 982.035783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 982.040923] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=113325
> [ 982.050294] (detected by 1, t=241580 jiffies, g=1561, q=3509)
> [ 982.056108] Task dump for CPU 0:
> [ 982.059321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 982.066359] Workqueue: events set_brightness_delayed
> [ 982.071302] Call Trace:
> [ 982.073739] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [..]
>
> Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow")
> Signed-off-by: Greentime Hu <[email protected]>
> ---
> drivers/irqchip/irq-sifive-plic.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index eaa3e9fe54e9..4048657ece0a 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -151,7 +151,7 @@ static int plic_set_affinity(struct irq_data *d,
> return -EINVAL;
>
> plic_irq_toggle(&priv->lmask, d, 0);
> - plic_irq_toggle(cpumask_of(cpu), d, 1);
> + plic_irq_toggle(cpumask_of(cpu), d, !irqd_irq_masked(d));
>
> irq_data_update_effective_affinity(d, cpumask_of(cpu));
>
> --
> 2.28.0
>

Looks good to me.

Reviewed-by: Anup Patel <[email protected]>

Regards,
Anup

2020-10-25 16:33:03

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH] irqchip/sifive-plic: Fix broken irq_set_affinity() callback

On Tue, 20 Oct 2020 16:15:32 +0800, Greentime Hu wrote:
> It will always enable the interrupt after calling plic_set_affinity()
> however it should set to it previous setting. Staying disabled or enabled.
>
> This patch can also fix this pwm hang issue in Unleashed board.
>
> [ 919.015783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 919.020922] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=105807
> [ 919.030295] (detected by 1, t=225825 jiffies, g=1561, q=3496)
> [ 919.036109] Task dump for CPU 0:
> [ 919.039321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 919.046359] Workqueue: events set_brightness_delayed
> [ 919.051302] Call Trace:
> [ 919.053738] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [ 982.035783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
> [ 982.040923] rcu: 0-...0: (0 ticks this GP)
> idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=113325
> [ 982.050294] (detected by 1, t=241580 jiffies, g=1561, q=3509)
> [ 982.056108] Task dump for CPU 0:
> [ 982.059321] kworker/0:1 R running task 0 30 2 0x00000008
> [ 982.066359] Workqueue: events set_brightness_delayed
> [ 982.071302] Call Trace:
> [ 982.073739] [<ffffffe000930d92>] __schedule+0x194/0x4de
> [..]

Applied to irq/irqchip-next, with some commit message adjustments.

[1/1] irqchip/sifive-plic: Fix broken irq_set_affinity() callback
commit: a7480c5d725c4ecfc627e70960f249c34f5d13e8

Cheers,

M.
--
Without deviation from the norm, progress is not possible.


Subject: [tip: irq/urgent] irqchip/sifive-plic: Fix broken irq_set_affinity() callback

The following commit has been merged into the irq/urgent branch of tip:

Commit-ID: a7480c5d725c4ecfc627e70960f249c34f5d13e8
Gitweb: https://git.kernel.org/tip/a7480c5d725c4ecfc627e70960f249c34f5d13e8
Author: Greentime Hu <[email protected]>
AuthorDate: Tue, 20 Oct 2020 16:15:32 +08:00
Committer: Marc Zyngier <[email protected]>
CommitterDate: Sun, 25 Oct 2020 12:33:07

irqchip/sifive-plic: Fix broken irq_set_affinity() callback

An interrupt submitted to an affinity change will always be left enabled
after plic_set_affinity() has been called, while the expectation is that
it should stay in whatever state it was before the call.

Preserving the configuration fixes a PWM hang issue on the Unleashed
board.

[ 919.015783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 919.020922] rcu: 0-...0: (0 ticks this GP)
idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=105807
[ 919.030295] (detected by 1, t=225825 jiffies, g=1561, q=3496)
[ 919.036109] Task dump for CPU 0:
[ 919.039321] kworker/0:1 R running task 0 30 2 0x00000008
[ 919.046359] Workqueue: events set_brightness_delayed
[ 919.051302] Call Trace:
[ 919.053738] [<ffffffe000930d92>] __schedule+0x194/0x4de
[ 982.035783] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 982.040923] rcu: 0-...0: (0 ticks this GP)
idle=7d2/1/0x4000000000000002 softirq=1424/1424 fqs=113325
[ 982.050294] (detected by 1, t=241580 jiffies, g=1561, q=3509)
[ 982.056108] Task dump for CPU 0:
[ 982.059321] kworker/0:1 R running task 0 30 2 0x00000008
[ 982.066359] Workqueue: events set_brightness_delayed
[ 982.071302] Call Trace:
[ 982.073739] [<ffffffe000930d92>] __schedule+0x194/0x4de
[..]

Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow")
Signed-off-by: Greentime Hu <[email protected]>
[maz: tidy-up commit message]
Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
drivers/irqchip/irq-sifive-plic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index eaa3e9f..4048657 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -151,7 +151,7 @@ static int plic_set_affinity(struct irq_data *d,
return -EINVAL;

plic_irq_toggle(&priv->lmask, d, 0);
- plic_irq_toggle(cpumask_of(cpu), d, 1);
+ plic_irq_toggle(cpumask_of(cpu), d, !irqd_irq_masked(d));

irq_data_update_effective_affinity(d, cpumask_of(cpu));