Shared IRQ
Hi, I would like to know if a different hardware can shared the same IRQ with another? Eg: inteldrm0 at vga1: apic 1 int 16 (irq 11) ppb1 at pci0 dev 28 function 1 Intel 82801GB PCIE rev 0x02: apic 1 int 16 (irq 11) uhci3 at pci0 dev 29 function 3 Intel 82801GB USB rev 0x02: apic 1 int 16 (irq 11) Thanks in advance. -- Joco Salvatti Graduated in Computer Science Federal University of Para - UFPA - Brazil E-Mail: salva...@gmail.com
Re: Shared IRQ
http://www.openbsd.org/faq/faq12.html 12.7.3 2009/5/14 Joco Salvatti salva...@gmail.com: Hi, I would like to know if a different hardware can shared the same IRQ with another? Eg: inteldrm0 at vga1: apic 1 int 16 (irq 11) ppb1 at pci0 dev 28 function 1 Intel 82801GB PCIE rev 0x02: apic 1 int 16 (irq 11) uhci3 at pci0 dev 29 function 3 Intel 82801GB USB rev 0x02: apic 1 int 16 (irq 11) Thanks in advance. -- Joco Salvatti Graduated in Computer Science Federal University of Para - UFPA - Brazil E-Mail: salva...@gmail.com
Re: Shared IRQ
From: Henry Sieff henry.si...@gmail.com To: Joco Salvatti salva...@gmail.com http://www.openbsd.org/faq/faq12.html 12.7.3 2009/5/14 Joco Salvatti salva...@gmail.com: Hi, I would like to know if a different hardware can shared the same IRQ with another? 12.7.3 is accurate, however there is a difference between 'can it' 'should it' and 'will it' 'should it?' - yes, it should 'can it?' - yes, it can 'will it?' - that's the tricky one. Some devices just don't share interrupts well. Perhaps it's shit hardware, a shit APIC, crappy BIOS, naff driver - whatever. PCI devices can theoretically share interrupts, but that doesn't necessarily mean they will. PK
Re: Shared IRQ
On Thu, May 14, 2009 at 8:27 AM, Peter Kay - Syllopsium syllops...@syllopsium.com wrote: From: Henry Sieff henry.si...@gmail.com To: Joco Salvatti salva...@gmail.com http://www.openbsd.org/faq/faq12.html 12.7.3 2009/5/14 Joco Salvatti salva...@gmail.com: Hi, I would like to know if a different hardware can shared the same IRQ with another? 12.7.3 is accurate, however there is a difference between 'can it' 'should it' and 'will it' 'should it?' - yes, it should 'can it?' - yes, it can 'will it?' - that's the tricky one. Some devices just don't share interrupts well. Perhaps it's shit hardware, a shit APIC, crappy BIOS, naff driver - whatever. PCI devices can theoretically share interrupts, but that doesn't necessarily mean they will. I have only ever had an issue with off-brand NIC's, personally. But you are of course correct - PCI devices are supposed to be able to share IRQ's, but that doesn't mean all manufacturers do interop testing to make sure that works.
Re: Shared IRQ
This makes no sense at all. On Thu, May 14, 2009 at 09:07:56AM -0700, Henry Sieff wrote: On Thu, May 14, 2009 at 8:27 AM, Peter Kay - Syllopsium syllops...@syllopsium.com wrote: From: Henry Sieff henry.si...@gmail.com To: Joco Salvatti salva...@gmail.com http://www.openbsd.org/faq/faq12.html 12.7.3 2009/5/14 Joco Salvatti salva...@gmail.com: Hi, I would like to know if a different hardware can shared the same IRQ with another? 12.7.3 is accurate, however there is a difference between 'can it' 'should it' and 'will it' 'should it?' - yes, it should 'can it?' - yes, it can 'will it?' - that's the tricky one. Some devices just don't share interrupts well. Perhaps it's shit hardware, a shit APIC, crappy BIOS, naff driver - whatever. PCI devices can theoretically share interrupts, but that doesn't necessarily mean they will. I have only ever had an issue with off-brand NIC's, personally. But you are of course correct - PCI devices are supposed to be able to share IRQ's, but that doesn't mean all manufacturers do interop testing to make sure that works.
Re: Shared IRQ
[cleaned up formatting, since I accidentally top-posed to begin with] On Thu, May 14, 2009 at 9:24 AM, Marco Peereboom sl...@peereboom.us wrote: I worte: I have only ever had an issue with off-brand NIC's, personally. But you are of course correct - PCI devices are supposed to be able to share IRQ's, but that doesn't mean all manufacturers do interop testing to make sure that works. This makes no sense at all. ? I have had occasional issues with PCI NIC's inexplicably refusing to send traffic if they shared an IRQ - this was not an OpenBSD issue, since in those cases the problem was not corrected by using a different OS. NIC functioned fine when IRQ was no longer shared. Now, I had always assumed it was because of a problem with the NIC itself. Apparently, I am about to find out I was wrong :-).
Re: Shared IRQ
On Thu, May 14, 2009 at 09:35:45AM -0700, Henry Sieff wrote: [cleaned up formatting, since I accidentally top-posed to begin with] On Thu, May 14, 2009 at 9:24 AM, Marco Peereboom sl...@peereboom.us wrote: I worte: I have only ever had an issue with off-brand NIC's, personally. But you are of course correct - PCI devices are supposed to be able to share IRQ's, but that doesn't mean all manufacturers do interop testing to make sure that works. This makes no sense at all. ? I have had occasional issues with PCI NIC's inexplicably refusing to send traffic if they shared an IRQ - this was not an OpenBSD issue, since in those cases the problem was not corrected by using a different OS. NIC functioned fine when IRQ was no longer shared. Now, I had always assumed it was because of a problem with the NIC itself. Apparently, I am about to find out I was wrong :-). This can not have been recent. Sure in them olden days on garbage like netware this was an issue but those days are long gone.
