fxkl4...@protonmail.com wrote: > On Tue, 20 Aug 2024, Dan Ritter wrote: > > > fxkl4...@protonmail.com wrote: > >> i have a video capture card with 4 separate chips > >> when i start up i get bttv0 - bttv3 > >> i'm getting a lot of errors in syslog on bttv2 and bttv3 > >> like > >> bttv: 2: timeout: drop=3888442 irq=27910652/28054718, risc=338f048c, bits: > >> HSYNC > >> bttv: 3: timeout: drop=3940265 irq=27929862/27929862, risc=33adc01c, bits: > >> HSYNC > >> > >> could it be related to interrupts and cpus > >> cat /proc/interrupts > >> CPU0 CPU1 CPU2 CPU3 > >> 16: 0 26950435 0 0 IO-APIC 16-fasteoi bttv1 > >> 17: 0 0 28079982 0 IO-APIC 17-fasteoi bttv2 > >> 18: 0 0 27950635 0 IO-APIC 18-fasteoi i801_smbus, > >> bttv3 > >> 19: 66003 0 0 0 IO-APIC 19-fasteoi bttv0 > >> > >> i notice bttv2 and bttv3 are on the same cpu > >> and bttv3 is sharing an interrupt > >> is this related to my timeout errors > >> if so is it correctable > > > > Depending on the hardware -- I don't remember the ins and outs > > of most video capture cards these days -- you should be able to > > set the interrupt per card either in hardware or at kernel > > module load time. > > > > This could certainly be an issue, especially on a relatively > > low-powered machine; if you don't have the irqbalance daemon > > installed, you might try that first. > > > > -dsr- > > > > i installed irqbalance and it dramatically reduced the errors > from 2-3 a minute to 1 every 3-4 minutes
OK, now you know it's an IRQ sharing problem. Look up docs for your card and driver module and see if you can push them to non-competing IRQs. If they are PCI rather than PCIe cards, you may need to physically switch slots, or there may be a BIOS change available. -dsr-
