This is a note to let you know that I've just added the patch titled irqchip/sifive-plic: Fix broken irq_set_affinity() callback to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: irqchip-sifive-plic-fix-broken-irq_set_affinity-call.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f4a8ef6867bf285e1c0a26f11388a90f7b958f49 Author: Greentime Hu <greentime.hu@xxxxxxxxxx> Date: Tue Oct 20 16:15:32 2020 +0800 irqchip/sifive-plic: Fix broken irq_set_affinity() callback [ Upstream commit a7480c5d725c4ecfc627e70960f249c34f5d13e8 ] 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 <greentime.hu@xxxxxxxxxx> [maz: tidy-up commit message] Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20201020081532.2377-1-greentime.hu@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c index eaa3e9fe54e91..4048657ece0ac 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));