* David Brownell <david-b@xxxxxxxxxxx> wrote: > On Monday 02 March 2009, Ingo Molnar wrote: > > > > > > The significant omission is lack of support for chaining > > > such threads. Example, an I2C device that exposes > > > several dozen IRQs with mask/ack/... operations that > > > require I2C access. > > > > Well, those are rarely used, embedded-only constructs - the main > > focus of IRQ threading patches are the more common patterns. > > Yes, mostly for embedded, where "system bus" more likely > means I2C than PCI. > > > > Since you care about them - could you please send patches on top > > of the IRQ threading patches to add support for them? > > I'll look at that, and try to prepare something on top > of the version of the threading patches that gets into > the -next tree. I got the impression there was going > to be a v3 of those patches soonish... Great! We'll sort out any conflicts so dont worry about that - you can pick up v2 just fine and post patches. > I expect there will be two basic parts of that work: > > - One to cope with the upcoming change to handle_irq(), > insisting that it live in hardirq context instead of > just an irqs-off context (and thereby preventing use > of standard chaining calls in irq threads, sigh). > > - Another to set up a chaining thread, since chain > setup bypasses setup_irq() and friends. If you mean to push the chaining bits into the IRQ thread too, i think the chaining bits actually should never be threaded. Is there a good reason to do that? It's not like they will really be preemptible (preempting a chaining thread would mean the whole demuxing chain is held up => bad). > That latter might touch what the v2 patches added, > since I'd want it to share code. Sure. > > - Dave > > p.s. Note that those changes would still leave the > lockdep bug around ... it will still be breaking > various drivers that use normal IRQs, by forcibly > enabling IRQF_DISABLED. it's not a bug - and i think Peter explained that already. It's not really breaking things either - we've had this for more than 2 years. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
