On Tue, Aug 22, 2017 at 3:40 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Aug 22, 2017 at 02:44:20PM -0600, David Mosberger wrote: >> > There was an option a while ago to turn USB irqs >> > into threaded irqs, do those work on your platform? If so, that might >> > help you out here. >> >> Do you mean this: >> >> https://lkml.org/lkml/2008/10/20/465 >> >> or is there something else/newer? > > I think there was something newer than that almost-a-decade-old thread, > but I don't remember. Look at what the RT kernel patch does, it might > be in there if it wasn't merged into the tree already. Actually, I'm not able to find much in this direction. Do you have something more specific I could be looking for? I don't think the RT patches would (readily) work for my case as I have a (soft-)realtime interrupt handler that depends on other drivers (e.g,. SPI and DMA). Looking at the OHCI and EHCI drivers more carefully, even if those were turned into threaded handlers, the problem would not (automatically) go away since they implicitly (OHCI) or explicitly (EHCI) disable (local) interrupt delivery while processing the URBs (in particular, while giving them back, which can trigger a lot of extra work). I'd very much appreciate any pointers to any work or thought that might have gone into improving this situation (in particular: returning URBs with interrupts enabled). The USB stack disabling interrupts for such extended periods of time surely isn't a problem just in my situation. --david -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
