Messages in this thread | | | Subject | Re: [GIT PATCH] more Driver core patches for 2.6.19 | From | Thomas Gleixner <> | Date | Wed, 13 Dec 2006 23:30:55 +0100 |
| |
On Thu, 2006-12-14 at 09:14 +1100, Benjamin Herrenschmidt wrote: > the edge flow is easy. the level one is: > > - IRQ happens > - kernel handler masks it and queue a msg for userland > - later on, userland gets the message, talks to the device, > (MMAP'ed mmio, acks the interrupt on the device itself) and > does an ioctl/syscall/write/whatever to tell kernel it's done > - kernel unmasks it.
That's simply not true.
- IRQ happens - kernel handler runs and masks the chip irq, which removes the IRQ request - user space message get queued or waiting reader woken - kernel handler returns IRQ_HANDLED, which reenables the irq in the PIC - user space handles the device - user space reenables the device irq
No need for an ioctl. Neither for edge nor for level irqs.
tglx
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |