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Re: Delivery Status Notification (Failure)
by Lucas Stach May 11, 2018

May 11, 2018

Am Freitag, den 11.05.2018, 13:39 +0100 schrieb Russell King - ARM Linux: > On Fri, May 11, 2018 at 05:07:37PM +0530, Pintu Kumar wrote: > > 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 ? > > IRQ affinity is only supported where interrupts are _directly_ wired to > the GIC. It's the GIC which does the interrupt steering to the CPU > cores. > > Interrupts on downstream interrupt controllers (such as GPCV2) have no > ability to be directed independently to other CPUs - the only possible > way to change the mapping is to move _all_ interrupts on that controller, > and any downstream chained interrupts at GIC level. > > Hence why Interrupt 295 has no irq_set_affinity function: there is no way > for the interrupt controller itself to change the affinity of the input > interrupt. The GPCv2 though is a secondary IRQ controller which has a 1:1 mapping of its input IRQs to the upstream GIC IRQ lines. Affinity can thus be handled by forwarding the request to the GIC by irq_chip_set_affinity_parent(). As this is handled correctly in the upstream kernel since the first commit introducing support for the GPCv2, it seems the issue is only present in some downstream kernel. Regards, Lucas

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Re: Delivery Status Notification (Failure)
by Pintu Kumar May 11, 2018

May 11, 2018

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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Not able to set smp_affinity for an IRQ on i.MX7
by Pintu Kumar May 11, 2018

May 11, 2018

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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Re: Kernelnewbies Digest, Vol 89, Issue 14
by Tran Ly Vu May 11, 2018

May 11, 2018

Hi, Is eudyptula challenge still alive? Thanks On 20 April 2018 at 00:00, <kernelnewbies-request(a)kernelnewbies.org> wrote: > Send Kernelnewbies mailing list submissions to > kernelnewbies(a)kernelnewbies.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > or, via email, send a message with subject or body 'help' to > kernelnewbies-request(a)kernelnewbies.org > > You can reach the person managing the list at > kernelnewbies-owner(a)kernelnewbies.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Kernelnewbies digest..." > > > Today's Topics: > > 1. How can I disable compile optimization in kernel for friendly > debugging, Thanks (sizel) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 19 Apr 2018 16:58:40 +0800 (CST) > From: sizel <sizel(a)163.com> > To: kernelnewbies <kernelnewbies(a)kernelnewbies.org> > Subject: How can I disable compile optimization in kernel for friendly > debugging, Thanks > Message-ID: <623d8297.8a0f.162dd208d7b.Coremail.sizel(a)163.com> > Content-Type: text/plain; charset="gbk" > > An HTML attachment was scrubbed... > URL: <http://lists.kernelnewbies.org/pipermail/kernelnewbies/ > attachments/20180419/53df7387/attachment-0001.html> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies(a)kernelnewbies.org > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > ------------------------------ > > End of Kernelnewbies Digest, Vol 89, Issue 14 > ********************************************* >

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Should I build the perf again when I change the kernel options?
by Gioh Kim May 11, 2018

May 11, 2018

Hi, Should I build the perf again when I change the kernel options? I have 4.14.34 kernel on my desktop and I built perf for my self. I'd like to change some options. Should I rebuild perf perf again? And another case. If there are two machines that have the same kernel version and different kernel options. Should I build the perf for each machines? Or can I build the perf on one machine and use it on another machine? Thank you in advance! -- Best regards, Gioh Kim

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kernel image path
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, When I do sb make in a Kernel sand box where is the resultant image stored ? -- Thanks and Regards, Sumit

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Is this maintainers list up to date ?
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, Can someone please confirm if this maintainer's list if up to date : https://github.com/torvalds/linux/blob/master/MAINTAINERS -- Thanks and Regards, Sumit

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Re: where to send patch
by Alex Arvelaez May 8, 2018

May 8, 2018

On May 7, 2018 5:23 PM, Sumit Kumar <sumit686215(a)gmail.com> wrote: > > Hi, > > When I use get_maintainer.pl script it give a list of names / addresses. > >1. Should I send to only one of them Send it to all of them, otherwise it's more likely it'll be lost in the noise. > 2. Should I put the first address in "To" field and the rest all in "CC" ? I believe you put the contributors in the To field and CC the relevant mailing list(s). There's a contribution guide you can read that explains this and more. (I'm paraphrasing so don't quote me) Regards, Alex

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(no subject)
by Vishnu Gopinath May 8, 2018

May 8, 2018

new in the field of linux kernal... how to start..from where to start

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where to send patch
by Sumit Kumar May 8, 2018

May 8, 2018

Hi, When I use get_maintainer.pl script it give a list of names / addresses. 1. Should I send to only one of them ? 2. Should I put the first address in "To" field and the rest all in "CC" ? -- Thanks and Regards, Sumit

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