From: Pintu Kumar <pintu.ping@gmail.com>
To: open list <linux-kernel@vger.kernel.org>,
linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kernelnewbies@kernelnewbies.org
Subject: Not able to set smp_affinity for an IRQ on i.MX7
Date: Fri, 11 May 2018 17:04:50 +0530 [thread overview]
Message-ID: <CAOuPNLjqJVsPOVPCnswtFyXudAJ88_F0QVUq-Z6qWE=UpH0mBA@mail.gmail.com> (raw)
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Hi,
I need one help.
I am using i.MX7 Sabre board with kernel version 4.1.15
Let's say I am interested in GPIO number: 21
I wanted to set CPU affinity for particular GPIO->IRQ number, so I tried
the below steps:
root@10:~# echo 21 > /sys/class/gpio/export
root@10:~# echo "rising" > /sys/class/gpio/gpio21/edge
root@10:~# cat /proc/interrupts | grep 21
47: 0 0 gpio-mxc 21 Edge gpiolib
root@10:~# cat /sys/class/gpio/gpio21/direction
in
root@10:~# cat /proc/irq/47/smp_affinity
3
root@10:~# echo 2 > /proc/irq/47/smp_affinity
-bash: echo: write error: Input/output error
But I get input/output error.
When I debug further, found that irq_can_set_affinity is returning 0:
[ 0.000000] genirq: irq_can_set_affinity (0): balance: 1, irq_data.chip:
a81b7e48, irq_set_affinity: (null)
[ 0.000000] write_irq_affinity: FAIL
I also tried first setting /proc/irq/default_smp_affinity to 2 (from 3).
This change is working, but the smp_affinity setting for the new IRQ is not
working.
When I try to set smp_affinity for mmc0, then it works.
# cat /proc/interrupts | grep mmc
295: 55 0 GPCV2 22 Edge mmc0
296: 0 0 GPCV2 23 Edge mmc1
297: 52 0 GPCV2 24 Edge mmc2
root@10:~# echo 2 > /proc/irq/295/smp_affinity
root@10:~#
So, I wanted to know what are the conditions for which setting smp_affinity
for an IRQ will work ?
Is there any way by which I can set CPU affinity to a GPIO -> IRQ ?
Whether, irq_set_affinity_hint() will work in this case ?
Thanks,
Pintu
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next reply other threads:[~2018-05-11 11:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-11 11:34 Pintu Kumar [this message]
[not found] ` <5af57fea.1c69fb81.885f0.2377.GMRIR@mx.google.com>
2018-05-11 11:37 ` Delivery Status Notification (Failure) Pintu Kumar
2018-05-11 12:39 ` Russell King - ARM Linux
2018-05-11 13:04 ` Lucas Stach
2018-05-11 14:37 ` Pintu Kumar
2018-05-14 12:12 ` Pintu Kumar
2018-05-14 13:11 ` Lucas Stach
2018-05-14 14:28 ` Pintu Kumar
2018-05-17 13:28 ` Pintu Kumar
2018-05-21 18:51 ` Pintu Kumar
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